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A useful starting point for designing advanced graphical user interfaces is the Visual Information-Seeking Mantra: Overview first, zoom and filter, then details-on- demand. But this is only a starting point in trying to understand the rich and varied set of information visualizations that have been proposed in recent years. This paper offers a task by data type taxonomy with seven data types (1-, 2-, 3-dimensional data, temporal and multi-dimensional data, and tree and network data) and seven tasks (overview, zoom, filter, details-on-demand, relate, history, and extract).
Also cross-referenced as ISR-TR-96-66
Keywords: interface design, human-computer interaction, visualization
Introduction [2:50] Elastic Windows for Rapid Multiple Window Management [6:49] Life-Lines: Visualizing Personal Histories [6:43] Designing Interfaces for Youth Services Information Management [4:57] Query Previews in Networked Information Systems : the Case of EOSDIS [4:32] Baltimore Learning Communities [8:50] Table of Contents of the 1995 HCIL Video Reports Table of Contents of the 1994 HCIL Video Reports Visual Information Seeking using the FilmFinder (Extract from the HCIL1994 Video Report) [6:12]
Keywords: Spatial Visualization Ability (SVA), visualization, User interfaces, navigation, interface apparency
What we see is not always what we get. This is the problem when the underlying structure of an interface is hidden from the user's view. Users high in Spatial Visualization Ability (SVA), are quick to learn the contingencies of these relationships and are not hindered by this problem. Low SVA users, however, have difficulty visualizing these contingencies and often get lost. We examined data for 97 undergraduate students to determine whether revealing hidden contingencies though visual cues would facilitate Low SVA users, enabling them to approach the level of performance of High SVA users on a computerized path finding task. It was found that increasing interface apparency does seem to benefit all users, but particularly those with Low SVA.
(Also cross-referenced as CAR-TR-824)
Keywords: text filtering, information seeking, User interfaces, information retrieval, user modeling, machine learning
This report develops a conceptual framework for text filtering practice and research, and reviews present practice in the field. Text filtering is an information seeking process in which documents are selected from a dynamic text stream to satisfy a relatively stable and specific information need. A model of the information seeking process is introduced and specialized to define information filtering. The historical development of text filtering is then reviewed and case studies of recent work are used to highlight important design characteristics of modern text filtering systems. Specific techniques drawn from information retrieval, user modeling, machine learning and other related fields are described, and the report concludes with observations on the present state of the art and implications for future research on text filtering.
(Also cross-referenced as CAR-TR-830)
(Also cross-referenced as EE TR-96-25)
(Also cross-referenced as CLIS TR-96-02)
Keywords: interface design, human-computer interaction, visualization, on-line library
Understanding and assessing user needs is the first step in interface design, and this report is one of the first milestones in the overall design effort. This assessment provides an informed basis for the interface design and evaluation to be done in the months to come. It was prepared under the LibraryÕs contract with the Human-Computer Interaction Laboratory (HCIL) at the University of MarylandÕs to work together to design an interface for the LibraryÕs National Digital Library (NDL) Program.
In order to determine user needs, HCIL conducted a survey of nine reading rooms with special emphasis on the Special Collections from which the content of the NDL will be drawn. HCIL also used questionnaires to reach remote audiences who may typify NDL users accessing the Library via the Internet. They also analyzed many of the documents available in the Reading Rooms, such as finding aids, other handouts, and user studies.
Keywords: Graphical user interfaces, evaluation tools, consistency, textual and visual style, assessment tools, metrics
Designing a user interface with a consistent visual design and textual properties with current generation GUI development tools is cumbersome. SHERLOCK, a family of consistency checking tools, has been designed to evaluate visual design and textual pro perties of interface, make the GUI evaluation process less arduous, and aid usability testing. SHERLOCK includes a dialog box summary table to pro vide a compact overview of visual properties of hundreds of dialog boxes of the interface. Terminology specific tools, like Interface Concordance, Terminology Baskets and Interface Speller have been developed. Button specific tools including Button Conco rdance and Button Layout Table have been created to detect variant capitalization, distinct typefaces, distinct colors, variant button sizes and inconsistent button placements. This paper describes the design, software architecture, and the use of SHERLOC K. An experiment with 60 subjects to study the effects of inconsistent interface terminology on user's performance showed 10-25% speedup for consistent interfaces. SHERLOCK was tested with four commercial prototypes; the corresponding outputs, analysis a nd feedback from designers of these applications is presented.
(Also cross-referenced as CAR-TR-828)
Keywords: legacy systems, information system, visualization, graphical user interfaces, navigation, timeline.
The Maryland Department of Juvenile Justice (DJJ) is seeking a new information system to replace its legacy system for youth case management. The major goal of the new information system is to improve the process of juvenile case management, and thus deliver more effective services to youths, by better facilitating the tracking of case information and the production and handling of case- related documents. The primary challenge in designing the new system is to integrate optimally the appropriate components of existing processes, information, and documents. Our approach has shown that fostering user discussion and review of existing documents is extremely valuable in defining existing processes and information requirements, and effectively highlights areas where valuable process changes can be made and what system features are needed to support them. Subsequently linking user requirements for documents with innovative graphic user interface techniques can integrate diverse information for users and can affect additional positive changes to organizational processes.
(Also cross-referenced as CAR-TR-827)
Keywords: information system, visualization, graphical user interfaces, navigation, timeline
To take advantage of todayÕs technology, many organizations are migrating from their legacy systems. With help from the Human-Computer Interaction Laboratory (HCIL) and Cognetics Corporation, the Maryland Department of Juvenile Justice (DJJ) is currently undergoing an effort to redesign their information system to take advantage of graphical user interfaces. As a research lab, HCIL identifies interesting research problems and then prototypes solutions. As a project matures, the exploratory prototypes are adapted to suit the end product requirements. This case study describes the life cycle of three DJJ prototypes: (1) LifeLines, which uses time lines to display an overview of a youth in one screen, (2) the DJJ Navigator, which helps manage individual workloads by displaying different user views, and (3) the ProgramFinder, a tool for selecting the best program for a youth.
(Also cross-referenced as CAR-TR-826)
Keywords: web pages, visualization, User interfaces, navigation,
The deluge of web pages has generated dystopian commentaries on the tragedy of the flood as well as utopian visions of harnessing the same flood for constructive purposes. Within this ocean of information there are also lifeboat web pages with design principles, but often the style parallels the early user interface writings in the 1970s. The well-intentioned Noahs who write from personal experience as website designers, often draw their wisdom from specific projects, making their advice incomplete or lacking in generalizability. Their experience is valuable but the paucity of empirical data to validate or sharpen insight means that some guidelines are misleading. As scientific evidence accumulates, foundational cognitive and perceptual theories will structure the discussion and guide designers in novel situations.
(Also cross-referenced as CAR-TR-824)
(Also cross-referenced as ISR-TR-96-40)
Keywords: Computerized medical records, visualization, User interfaces, navigation, timeline
LifeLines provide a general visualization environment for personal histories. We explored its use for medical patient records. A one screen overview of the record using timelines provides direct access to the data. Problems, hospitalization and medications can be represented as horizontal lines, while icons represent discrete events such as physician consultations (and progress notes) or tests. Line color and thickness can illustrate relationships or significance. Techniques are described to display large records. Rescaling tools and filters allow users to focus on part of the information, revealing more details.
Computerized medical records pose tremendous problems to system developers. Infrastructure and privacy issues need to be resolved before physicians can even start using the records. Non-intrusive hardware is required for physicians to do their work (i.e. interview patients) away from their desk and cumbersome workstations. But all the efforts to solve those problems will only succeed if appropriate attention is also given to the user interface design [1][8]. Long lists to scroll, clumsy search, endless menus and lengthy dialogs will lead to user rejection. But techniques are being developed to summarize, filter and present large amount of information, leading us to believe that rapid access to needed data is possible with careful design.
While more attention is now put on developing standards for gathering medical records we found that very little effort had been made to design appropriate visualization and navigation techniques to present and explore personal history records. An intuitive approach to visualizing histories is to use graphical time series. The consistent, linear time scale allows comparisons and relations between the quantities displayed. Data can be graphed on the timeline to show time series of quantitative data. Highly interactive interfaces turn the display into a meaningfully structured menu with direct access to the data needed to review a problem or conduct the diagnosis.
Also cross-referenced as CAR-TR-819
Keywords: Browsing, Digital Library, Image Database, World-Wide Web, Information Exploration, Information Retrieval, Internet, Medical Image, Remote Access, User Interface, Visualization
This paper proposes a user interface for remote access of the National Library of MedicineÕs Visible Human digital image library. Users can visualize the library, browse contents, locate data of interest, and retrieve desired images. The interface pr esents a pair of tightly coupled views into the library data. The overview image provides a global view of the overall search space, and the preview image provides details about high resolution images available for retrieval. To explore, the user sweeps the views through the search space and receives smooth, rapid, visual feedback of contents. Desired images are automatically downloaded over the internet from the library. Library contents are indexed by meta-data consisting of automatically generated miniature visuals. The interface software is completely functional and freely available for public use, at: http://www.nlm.nih.gov/.
(Also cross-referenced as CAR-TR-798)
(Also cross-referenced as ISR-TR-95-99)
Keywords: electronic classrooms, teaching/learning, multimedia
In our seven year effort to build electronic classrooms we tried to balance the pursuit of new technologies with the exploration of new teaching/learning styles while providing the necessary infrastructure for faculty training and support, and collecti ng ample evaluation data to guide our transformation. This experience has led to a growing community of faculty users, widespread student acceptance, and administration support for expansion.
After four years of usage by 44 faculty (20 tenured, 9 untenured, 15 other staff) from 16 departments offering 122 courses with over 4010 students we are ready to report on the lessons we have learned. Courses filled most slots from 8am to 10pm, and were as diverse as The Role of Media in the American Political Process, Chinese Poetry into English, Marketing Research Methods, Database Design, and Saving the Bay.
(Also cross-referenced as CAR-TR-797)
Keywords: organizational goals, human needs, individual rights, Social Impact, information systems, development process, Maryland Department of Juvenile Justice
"The real question before us lies here: do these instruments further life and enhance its values, or not?Ó - Mumford (1934) p. 318 Computers have become an integral part of our everyday lives. Banks, airlines, motor vehicle administrations, police departments, Social Security, and the Internal Revenue Service all depend on computers. From their introduction, people have questioned the impact computers will have on society. We believe it is our responsibility as system designers to achieve organizational goals while serving human needs and protecting individual rights. The proposed Social Impact Statements (Shneiderman, 1990) woul d identify the impacts of information systems on direct and indirect users, who may be employees or the public. This paper proposes a framework for implementing Social Impact Statements for federal and local government agencies and regulated industries, with optional participation by the other privately held corporations. A Social Impact Statement should describe the new system and its benefits, acknowledge concerns and potential barriers, outline the development process, and address fundamental principl es. Examples from our work with the Maryland Department of Juvenile Justice are offered.
Also cross-referenced as CAR-TR-796
Keywords: Dynamic Queries, Evaluating user interfaces, User interfaces, Widget, Metric, data visualization, Human- Computer Interaction, WWW, Network, file manager
49 minute video of the labs work over the past year. Topics are: ¥Introduction and table of contents - Ben Shneiderman ¥Using Dynamic Queries for Youth Services Information - Anne Rose, Ajit Vanniamparampil ¥Life-Lines: Visualizing Personal Histories - Brett Milash, Catherine Plaisant, Anne Rose ¥Dynamic Queries and Pruning for Large Tree Structures - Harsha Kumar ¥Browsing Anatomical Image Databases : the Visible Human - Flip Korn, Chris North ¥Spinning Your Web: WWW Interface Design Issues - Vince Boisselle ¥BizView : Managing Business and Network Alarms - Catherine Plaisant, Wei Zhao and Rina Levy ¥Animated Specifications Using Interaction Object Graphs - David Carr ¥WinSurferª: Treemaps for Replacing the Windows File Manager - Marko Teittinen
(Also cross-referenced as CAR-TR-795)
Keywords: Evaluating user interfaces, User interfaces, Human-Computer Interaction,, Widget, data visualization, information management, network, Treemaps, Graphical macros, pixel-pattern, Triggers, distance learning, dynamic queries, HomeFinder, health statistics atlas, CHI '94
80 minute video demonstrations of the past year's research Topics are: ¥Introduction and table of contents - Ben Shneiderman, [3:18] ¥Visual information seeking using the FilmFinder - Christopher Ahlberg, Ben Shneiderman, [6:12] ¥Organization overviews and role management-Inspiration for future desktop environments - Catherine Plaisant, Ben Shneiderman, [9:39] ¥Visual decision-making: using treemaps for the analytic hierarchy process - Toshiyuki Asahi, Ben Shneiderman, David Turo, [8:34] ¥Visual information management for satellite network configuration-Catherine Plaisant, Harsha Kumar, Marko Teittinen, Ben Shneiderman, [8:49] ¥Graphical macros: a technique for customizing any application using pixel-pattern matching-Richard Potter, [9:49] ¥Education by engagement and construction: can distance learning be better than face to face?- Ben Shneiderman, [15:00] ¥Dynamic queries demos: revised HomeFinder and text version plus health statistics atlas-Ben Shneiderman, [9:40] Dynamic Queries are user controlled displays of visual or textual information. Ben Shneiderman presents the HomeFinder (developed by Chris Williamson), followed by the text version (Vinit Jain) and the Health Statistics Atlas (Catherine Plaisant and Vinit Jain). ¥CHI '94 slide and video show- [9:12]Open House '94 Video
(Also cross-referenced as CAR-TR-794)
Keywords: Layout Appropriateness, Evaluating user interfaces, User interfaces, Widget, Dynamic Queries, Treemaps,HyperCourseware, Grateful Med
¥Introduction and table of contents - Ben Shneiderman, [4:00] ¥Dynamaps: dynamic queries on a health statistics atlas - Catherine Plaisant and Vinit Jain, [6:34], ¥Hierarchical visualization with Treemaps: making sense of pro basketball data - Dave Turo, [10:47], ¥TreeVizª: file directory browsing - Brian Johnson, [10:04], ¥HyperCourseware: computer integrated tools in the AT&T Teaching Theater - Kent Norman, [7:08], ¥Improving access to medical abstracts: Grateful Med Interface prototype - Gary Marchionini, [6:08], ¥Layout appropriateness: guiding interface desi gn with simple task descriptions - Andrew Sears, [4:00]
(Also cross-referenced as CAR-TR-793)
Keywords: Dynamic Queries, direct manipulation, Treemaps, visualization, directory browsing, Widget, boolean queries, AT&T Teaching Theater, public access catalog, Remote Direct Manipulation, telepathology, AT&T Teaching Theater, pixel pattern, triggers
Introduction - Ben Shneiderman, [3:00], ¥Dynamic Queries: database searching by direct manipulation - Ben Shneiderman, Chris Williamson, Christopher Ahlberg, [10:55], ¥Treemaps for visualizing hierarchical information - Ben Shneiderman, Brian Johnson, Dave Turo, [11:25], ¥Three strategies for directory browsing - Rick Chimera, [10:30], ¥Filter-Flow metaphor for boolean queries - Degi Young, Ben Shneiderman, [6:35], ¥The AT&T Teaching Theater: active learning through computer supported collaborative courseware - Kent Norman, [8:25], ¥ACCESS: an online public access catalog at the Library of Congress - Gary Marchionini, [8:15] ¥Remote Direct Manipulation: a telepathology workstation - Catherine Plaisant, Dave Carr, [7:30], ¥Guiding automation with pixels: a technique for programming in the user interface - Richard Potter, [11:50]
(Also cross-referenced as CAR-TR-792)
Keywords: home control, schedulers, Evaluating user interfaces, User interfaces, Widget, Touchscreen, toggles, home automation, fingerpainting, keyboards, Pie menus, browsing, toggles, ables of contents
Introduction - Ben Shneiderman, ¥Scheduling home control devices - Catherine Plaisant, Ben Shneiderman, ¥Touchscreen toggles - Catherine Plaisant , ¥A home automation system - Reuel Launey (Custom Command Systems), ¥PlayPen II (now known as PenPlay II) : A novel fingerpainting program - Andrew Sears, Ben Shneiderman, ¥Touchscreen keyboards - Andrew Sears, Ben Shneiderman, ¥Pie menus - Don Hopkins, ¥Three interfaces for browsing tables of contents - Rick Chimera
(Also cross-referenced as CAR-TR-791)
Keywords: direct manipulation, dynamic query, information system, network, preview bar, query preview, science data, voume preview, user interface
In a networked information system, there are three major obstacles facing users in a querying process: slow network performance, large data volume and data complexity. In order to overcome these obstacles, we propose a two-phase approach to query form ulation: Query Preview and Query Refinement. In the Query Preview phase, users formulate an initial query by selecting desired attribute values. The volume of matching data sets is shown graphically on preview bars which aid users to rapidly eliminate undesired data sets, and focus on a manageable number of relevant data sets. Query previews also prevent wasted steps by eliminating zero-hit queries. When the estimated number of data sets is low enough, users submit the initial query to the network, which returns the metadata of the data sets for the Query Refinement phase. Using this approach, we developed dynamic query user interfaces allowing users to formulate their queries using direct manipulation in an exploratory manner across a networked environment.
(Also cross-referenced as CAR-TR-788
(Also cross-referenced as ISR-TR-95-90
Keywords: Visualization, history, timeline, personal record, justice, medical record screen design, overview, screen management
LifeLines provide a general visualization environment for personal histories that can be applied to medical and court records, professional histories and other types of biographical data. A one screen overview shows multiple facets of the records. Aspects, for example medical conditions or legal cases, are displayed as individual time lines, while icons indicate discrete events, such as physician consultations or legal reviews. Line color and thickness illustrate relationships or significance, scaling tools and filters allow users to focus on part of the information. LifeLines reduce the chances of missing information, facilitate spotting anomalies and trends, streamline access to details, while remaining tailorable and easily sharable between applications. The paper describes the use of LifeLines for youth records of the Maryland Department of Juvenile Justice and also for medical records. User's feedback was collected using a Visual Basic prototype for the youth record. Techniques to deal with complex records are reviewed and issues of a standard personal record format are discussed.
additional reference numbers in the format of the next line
(Also cross-referenced as CAR-TR-787, ISR-TR-95-88)
Keywords: Window Manager, CAD, Task Switching, Multi-window operations Personal Role Manager, Programming Environment, Navigation Problem
Most windowing systems follow the independent overlapping windows approach, which emerged as an answer to the needs of the 80s' applications and technology. Advances in computers, display technology, and the applications demand more functionality from window management systems. Based on these changes and the problems of current windowing approaches, we have updated the requirements for multi-window systems to guide new methods of window management. We propose elastic windows with improved spatial layout and rapid multi-window operations. Multi-window operations are achieved by issuing operations on a hierarchically organized group of windows in a space-filling tiled layout. Sophisticated multi-window operations like Hook, Pump, Minimize, Restore, Move and Relocate have been developed to handle fast task-switching and to structure the work environment of users to their rapidly changing needs. We claim that these multi-window operations and the tiled layout decrease the cognitive load on users. Users found our prototype system to be comprehensible and enjoyable as they playfully explored the way multiple windows are reshaped.
(Also cross-referenced as CAR-TR-786, ISR-TR-95-89)
Keywords: Browsing, Hierarchical, Dynamic Queries, Pruning, Tree-browser, visualization tool, filtering
Users often must browse hierarchies with thousands of nodes in search of those that best match their information needs. The PDQ Tree-browser (Pruning with Dynamic Queries) visualization tool was specified, designed and developed for this purpose. This tool presents trees in two tightly-coupled views, one a detailed view and the other an overview. Users can use dynamic queries, a method for rapidly filtering data, to filter nodes at each level of the tree. The dynamic query panels are user-customizable. Subtrees of unselected nodes are pruned out, leading to compact views of relevant nodes. Usability testing of the PDQ Tree-browser, done with 8 subjects, helped assess strengths and identify possible improvements. The PDQ Tree-browser was used in Network Management (600 nodes) and UniversityFinder (1100 nodes) applications. A controlled experiment, with 24 subjects, showed that pruning significantly improved performance speed and subjective user satisfaction. Future research directions are suggested.
(Also cross-referenced as CAR-TR-772)
(Also cross-referenced as ISR-TR-95-53)
Keywords: Role manager, personal roles, desktop metaphor, coordination, window management
In our exploration of future work environments for the World Bank we propose two concepts. Organization overviews provide a consistent support to present the results of a variety of manual or semi-automated searches. This view can be adapted or expanded for each class of users to finally map the multiple personal roles an individual has in an organization. After command line interfaces, graphical point and click interfaces, and the current "docu-centric" designs, the natural direction is towards a role-centered approach where we believe the emphasis is on the management of those multiple roles. Each role involves coordination with groups of people and accomplishment of tasks within a schedule.
(Also cross-referenced as CAR-TR-771)
Keywords: Automated metrics, consistency checking tools, concordance tools, spatial and textual evaluation tools, user interface
Incorporating evaluation metrics with GUI development tools will help designers create consistent interfaces in the future. Complexity in design of interfaces makes efficient evaluation impossible by a single consistency checking evaluation tool. Our f ocus is on developing a family of evaluation tools in order to make the evaluation process less cumbersome. We have developed a dialog box typeface and color table to facilitate detection of anomalies in color, font, font size, and font style. Concordance tools have been developed to spot variant capitalization and abbreviations globally in the interface and specifically in the button widgets. As buttons are frequently used widgets, a button layout table has been created to spot any inconsistencies in height, width and relative position between a given group of buttons if present. Finally, a terminology basket tool has been created to identify unwanted synonyms of computer related terms used in the interface which may be misleading to the end user.
(Also cross-referenced as CAR-TR-770)
(Also cross-referenced as ISR-TR-95-52)
Keywords: Information System for Youth Services (ISYS), Assessing users' satisfaction, User interfaces, Questionnaire for User Interaction Satisfaction (QUIS 5.5)
In this investigation, the Questionnaire for User Interaction Satisfaction (QUIS 5.5), a tool for assessing users' subjective satisfaction with specific aspects of the human/computer interface was used to assess the strengths and weaknesses of the Info rmation System for Youth Services (ISYS). ISYS is used by over 600 employees of the Maryland State Department of Juvenile Services (DJS) as a tracking device for juvenile offenders. Ratings and comments were collected from 254 DJS employees who use ISYS. The overall mean rating across all questions was 5.1 on a one to nine scale. The ten highest and lowest rated questions were identified. The QUIS allowed us to isolate subgroups which were compared with mean ratings from four measures of specific interfac e factors. The comments obtained from users provided suggestions, complaints and endorsements of the system.
Also cross-referenced as CAR-TR-768
Keywords: User Interface Reengineering, usability, user satisfaction, data display and entry, consistency, messages, documentation, system access
User interface technology has advanced rapidly in recent years. Incorporating new developments in existing systems could result in substantial improvements in usability, thereby improving performance and user satisfaction, while shortening training an d reducing error rates. Our focus is on low-effort high-payoff improvements to aspects such as data display and entry, consistency, messages, documentation, and system access. This paper provides guidelines for managers and designers responsible for use r interface reengineering, based on the experience we gained from six projects, and compiles our observations, recommendations and outcomes.
(Also cross-referenced as CAR-TR-767)
Keywords: Ethnography, Anthropology, Participant observation, Design methods, Redesign, Evaluation, User Studies
Methods for observing software users in the workplace will become increasingly important as the number of people using computers grows and developers improve existing systems. Successful redesigns rely, in part, on complete and accurate evaluations of the existing systems. Based on our evaluation experience, we have derived a set of practical guidelines to be used by designers in preparing for the evaluation, performing the field study, analyzing the data, and reporting the findings. By providing a general framework based on ethnographic research, we hope to reduce the likelihood of some common problems, such as overlooking important information and misinterpreting observations. Examples from our ongoing work with the Maryland Department of Juvenile Services are used to illustrate the proposed guidelines.
(Also cross-referenced as CAR-TR-765)
Keywords: button bars, menus, User interfaces, pull-down menu selection, interaction methods, widget
Button bars are a relatively new interaction method intended to speed up application use as compared to pull-down menus. This exploratory study compares three command selection methods: pull-down menus, button bars, and user choice of pull-down menus or button bars. Effectiveness was measured in two ways: speed of selection and error rate. 15 participants performed 15 word processor related tasks. Results show that in frequently used functions, such as character attribute selection (bold, italic, u nderline, etc.), button bars are faster. There were no statistically significant differences in error rates between the three interaction methods.
(Also cross-referenced as CAR-TR-764)
Keywords: Graphic User Interfaces (GUIs), analysis metrics, Evaluating user interfaces,, User interfaces redesign
The next generation of Graphic User Interfaces (GUIs) will offer rapid access to perceptually-rich, information abundant, and cognitively consistent interfaces. These new GUIs will be subjected to usability tests and expert reviews, plus new analysis methods and novel metrics to help guide designers. We have developed and tested first generation concordance tools to help developers to review terminology, capitalization, and abbreviation. We have also developed a dialog box summary table to help deve lopers spot patterns and identify possible inconsistencies in layout, color, fonts, font size, font style, and ordering of widgets. In this study we also explored the use of metrics such as widget counts, balance, alignment, density, and aspect ratios to provide further clues about where redesigns might be appropriate. Preliminary experience with several commercial projects is encouraging.
Also cross-referenced as CAR-TR-763
Also cross-referenced as ISR-TR-95-51
Keywords: Graphical Widgets, Specification, Interaction, Visualization, Objects, Object Graphs, Graphs
This document describes five widgets that have been developed at the Human-Computer Interaction Laboratory of the University of Maryland. These widgets are a range selection slider, a two-level alpha-slider, a secure switch , a tree viewer and a treemap viewer. The last two use the same tree representation and can be used as alternate visualizations of the same hierarchy. In addition, a system for widget specification is introduced and each widget is specified using this system.
(Also cross-referenced as CAR-TR-734)
(Also cross-referenced as ISR-TR-94-69)
Keywords: Visualization, treemap, analytic hierarchy process, AHP,, decision support, HCIL
Treemaps, a visualization method for large hierarchical data spaces, are used to augment the capabilities of the Analytic Hierarchy Process (AHP) for decision-making. Two direct manipulation tools, presented metaphorically as a ÒpumpÓ and a Òhook,Ó were developed and applied to the treemap to support AHP sensitivity analysis. Users can change the importance of criteria dynamically on the two-dimensional treemap and immediately see the impact on the outcome of the decision. This fluid process dramatically speeds up exploration and provides a better understanding of the relative impact of the component criteria. A usability study with 6 subjects using a prototype AHP application showed that treemap representation was acceptable from a visualization and data operation standpoint.
(Also cross-referenced as ISR-TR-94-45)
(Also cross-referenced as CAR-TR-719)
Keywords: Information Visualization, Network Management
Current network management systems rely heavily on forms in their user interfaces. the interfaces reflect the intricacies of the network hardware components but provide little support for guiding users through tasks. There is a scarcity of useful graphical visualizations and decision-support tools.
We applied a task-oriented approach to design and implemented the user interface for a prototype network configuration management system. Our user interface provides mulitple overviews of the network (with potentially thousands of nodes) and the relevant configuration tasks (queries and updates). We propose a unified interface for exploration, querying, data entry and verification. Compact color-coded treemaps with dynamic queries allowing user-controlled filtering and animation of the data display proved well-suited for representing the multiple containment hierarchies in networks. Our Tree-browser applied the conventional node-link visualization of trees to show hardware containment hierarchies. Improvements to conventional scrollbar- browsers included tightly coupled overviews and detailed views. This visual interface, implemented with Galaxy and the University of Maryland Widget Library(TM), has received enthusiastic feedback from the network management community. This application-specific paper has design paradigms that should be useful to designers of varied systems.
(Also cross-referenced as: CAR-TR-716)
(Also cross-referenced as: ISR-TR-94-45)
Keywords: Dynamic Queries, data structures, main memory database,, search overhead quantification, storage overhead quantification
Dynamic Queries is a querying technique for doing range search on multi-key data sets. It is a direct manipulation mechanism where the query is formulated using graphical widgets and the results are displayed graphically preferably within 100 millisec onds. This paper evaluates four data structures, the multilist, the grid file, k-d tree and the quad tree used to organize data in high speed storage for dynamic queries. The effect of factors like size, distribution and dimensionality of data on the storage o verhead and the speed of search is explored. Analytical models for estimating the storage and the search overheads are presented, and verified to be correct by empirical data. Results indicate that multilists are suitable for small (few thousand points) data sets irrespective of the data distribution. For large data sets the grid files are excellent for uniformly distriubuted data, and trees are good for skewed data distributions. There was not significant difference in performance between the tree st ructures.%X additional reference numbers in the format of the next line
Also cross-referenced as CAR-TR-715
Also cross-referenced as ISR-TR-94-47
Also cross-referenced as CS-TR-3133
Also cross-referenced as CAR-TR-685
Also cross-referenced as ISR-TR-93-73
Keywords: Smooth Zooming, Starfield, Information Visualization, User Interface, Interactive information visualization
This paper discusses the design and implementation of interactive smooth zooming of a starfield display. A starfield display is a two dimensional scatterplot of a multidimensional database where every item from the database is represented as a small colored glyph whose position is determined by its ranking along ordinal attributes of the items laid out on the axes. One way of navigating this visual information is by using a zooming tool to incrementally zoom in on the items by varying the attribute range on either axis independently - such zooming causes the glyphs to move continuously and to grow or shrink.
To get a feeling of flying through the data, users should be able to track the motion of each glyph without getting distracted by flicker or large jumps - conditions that necessitate high display refresh rates and closely spaced glyphs on successive frames. Although the use of high-speed hardware can achieve the required visual effect for small databases, the twin software bottlenecks of rapidly accessing display items and constructing a new display image fundamentally retard the refresh rate. Our work explores several methods to overcome these bottlenecks, presents a taxonomy of various zooming methods and introduces a new widget, the zoom bar, that facilitates zooming.
(Also cross-referenced as CAR-TR-714)
(Also cross-referenced as ISR-TR-94-46)
Keywords: Personal Role Manager, desktop metaphor, graphic user interface,, coordination, computer supported cooperative work, HCIL
Personal computer users typically manage hundreds of directories and thousands of files with hierarchically structured file managers, plus archaic cluttered-desktop window managers, and iconic representations of applications. These users must deal with the annoying overhead of window housekeeping and the greater burden of mapping their organizational roles onto the unnecessarily rigid hierarchy. An alternate approach is presented, Personal Role Manager (PRM), to structure the screen layout and the interface tools to better match the multiple roles that individuals have in an organization. Each role has a vision statement, schedule, hierarchy of tasks, set of people, and collection of documents.
(Also cross-referenced as ISR-TR-94-48)
(Also cross-referenced as CAR-TR-713)
Keywords: Image browser, Taxonomy, Specifications
Image browsing is necessary in numerous applications. Designers have merely used two one-dimensional scroll bars or they have made ad hoc designs for a two-dimensional scroll bar. However, the complexity of two-dimensional browsing suggests that more careful analysis, design, and evaluation might lead to significant improvements. We present a task taxonomy for image browsing, suggest design features and guidelines, assess existing strategies, and introduce an informal specification technique to describe the browsers.
(Also cross-referenced as CAR-TR-712)
(Also cross-referenced as ISR-TR-94-47)
Keywords: Telepathology, Remote Microscope, Exploring Images, Tele-operated microscope, User interface, human-computer interaction
Dynamic telepathology uses a tele-operated microscope to allow pathologists to view samples at a remote location. However, time delays introduced by remote operation have made use of a commercial dynamic telepathology system difficult and frustrating. This paper describes experiments to evaluate and redesign the user interface. We also make recomendations for further automation to support the pathology process and increase the usefulness of the system.
Copyright, 1994, by David Carr, Catherine Plaisant, and Hiroaki Hasegawa
All rights reserved
(Also cross-referenced as CAR-TR-708)
Keywords: User interface specification, user interface design
User Interface Management Systems have signigicantly reduced the effort required to build a user interface. However, current systems assume a set of standard "widgets" and make no provisions for defining new ones. This forces the user interface designers to either do without or laboriously build new widgets with code. The Interface Objects Graph is presented as a method for specifying and communicating the design of innteraction objects or widgets. Two sample specifications are presented, one for a secure switch and the other for a two dimensional graphical browser.
(Also cross-referenced as CAR-TR-687)
Keywords: Data structures, Dynamic Queries
Dynamic Queries is a querying technique for doing range search on multi-key data sets. It is a direct manipulation mechanism where the query is formulated using graphical widgets and the results are displayed graphically preferably within 100 milliseconds.
This paper evaluates four data structures, the multilist, the grid file, k-d tree and the quad tree used to organize data in high speed storage for dynamic queries. The effect of factors like size, distribution and dimensionality of data on the storage overhead and the speed of search is explored. Analytical models for estimating the storage and search overheads are presented, and verified to be correct by empirical data. Results indicate that multilists are suitable for small (few thousand points) data sets irrespective of the data distribution. For large data sets the grid files are excellent for uniformly distributed data, and trees are good for skewed data distributions. There was no significant difference in performance between the tree structures.
(Also cross-referenced as CAR-TR-685)
(Also cross-referenced as ISR-TR-93-73)
Keywords: Alphaslider, widget, selection technology, menus, dynamic queries
Research has suggested that rapid, serial, visual presentation of text (RSVP) may be an effective way to scan and search through lists of text strings in search of words, names, etc. The Alphaslider widget employs RSVP as a method for rapidly scanning and searching lists or menus in a graphical user interface environment. The Alphaslider only uses an area less than 7 x 2.5 cm2. The tiny size of the Alphaslider allows it to be placed on a credit card, on a control panel for a VCR, or as a widget in a direct manipulation based database interface. An experiment was conducted with four Alphaslider designs which showed that novice Alphaslider users could locate one item in a list of 10,000 film titles in 24 seconds on average, an expert user in about 13 seconds.
(Also cross-referenced as CAR-TR-684)
(Also cross-referenced as ISR-TR-93-72)
Keywords: Visual, Dynamic Query Filters, Starfield Displays, HCIL
This paper offers new principles for visual information seeking (VIS). A key concept is to support browsing, which is distinguished from familiar query composition and information retrieval because of its emphasis on rapid filtering to reduce result sets, progressive refinement of search parameters, continuous reformulation of goals, and visual scanning to identify results. VIS principles developed include: dynamic query filters (query parameters are rapidly adjusted with sliders, buttons, maps, etc.), starfield displays (two- dimensional scatterplots to structure result sets and zooming to reduce clutter), and tight coupling (interrelating query components to preserve display invariants and support progressive refinement combined with an emphasis on using search output to foster search input). A FilmFinder prototype using a movie database demonstrates these principles in a VIS environment.
(Also cross-referenced as CAR-TR-638)
(Also cross-referenced as ISR-TR-93-71)
Keywords: HCIL, HyperTools, HyperText, electronic documents
The most important factor determining the usability of electronic documents (e.g. hypertexts) is neither the set of links within the material nor the structure of the database but the availability ÒhypertoolsÓ defined as a vast range of electronic tools to support a diversity of reading activities. To illustrate this point, an analysis is undertaken of reading done for the purpose of using the information within a document to assist in tasks involving planning, decision making, and problem solving. Secondly, many readers start with the goals of finding, comparing, and evaluating information. Tools can help them realize these goals by supporting the activities of searching, collecting, and manipulating information. Other tools help people explore task requirements, enable them to preplan details of their interaction with the text, enhance their use of other tools, and optimize their screen-based working environment. It is argued that the support available for people working with electronic texts will not only offer many of of the functions available to readers of printed text, but electronic tools will also offer functionality that has no close counterpart in printed media. Consequently, hypertools will change the way readers do familiar tasks and facilitate tasks which are exceedingly difficult to accomplish when working with information on paper.
(Also cross-referenced as CAR-TR-675)
Keywords: Searching Sliders Query Interface Direct-manipulation
AlphaSlider is a query interface that uses a direct manipulation slider to select words, phrases, or names from an existing list. This paper introduces a prototype of AlphaSlider, describes the design issues, reports on an experimental evaluation, and offers directions for further research. The experiment tested 24 subjects selecting items from lists of 40, 80, 160, and 320 entries. Mean selection times only doubled with the 8-fold increase in list length. Users quickly accommodated to this selection method.
(Also cross-referenced as CAR-TR-637)
(Also cross-referenced as ISR-TR-93-52)
Keywords: HCIL, Teaching Theater, Evaluation of the software
The AT&T Teaching Theater is a highly interactive, multimedia electronic classroom at the University of Maryland offering instructors many new and creative teaching opportunities. Although this technology may hold many exciting possibilities, it is important to not lose sight of the main objective of any teaching facility - the students. Therefore, the important questions are: "How do students rate the AT&T Teaching Theater? What are their opinions of the various types of software programs currently offered? Do they facilitate or interfere with the learning process?" This paper discusses the results from a survey of students who attended classes in the AT&T Teaching Theater, Fall semester, 1992. A comparison among the different types of software used by the various instructors is the focus for this evaluation. In particular, HyperCourseware, a program providing an "electronic infrastructure" for computer based education will be at the center of this comparison. HyperCourseware is a "work in progress" and is one of the few software packages used in the electronic classroom designed with the Teaching Theater in mind. The findings from this paper will be used to determine where improvements need to be made in order to benefit the students and to make the most of the technology offered in the AT&T Teaching Theater in the future.
(Also cross-referenced as CAR-TR-672)
Keywords: pixels pattern matching, programming by demonstration, Triggers, device-level algorithms, just in time programming
Triggers is a programming system that shows how simple pattern matching applied to the pixels on a computer screen can effectively access data that is otherwise hidden inside an application program and unavailable to other programming by demonstration systems. Triggers invokes operators in applications by simulating keyboard and mouse actions, and accesses data through the pixel representations on the computer screen. Triggers extends the record/playback style popularized by keyboard macros. Triggers shows that pixel-based device-level algorithms exist, are understandable, can be easily implemented, and can allow a programming system to process data in situations where it would otherwise be impossible.
(Also cross-referenced as CAR-TR-658)
Keywords: Dynamic queries, database search, information retrieval, direct manipulation, user interface, Human-computer interaction, visual languages, visual information seeking
The capacity to incrementally adjust a query (with sliders, buttons, selections from a set of discrete attribute values, etc.) coupled with a visual display of results that are rapidly updated, dramatically changes the information seeking process. Dynamic queries on the chemical table of elements, computer directories, and a real estate database were built and tested in three separate exploratory experiments. Preliminary results show highly significant performance improvements and user enthusiasm more commonly seen with video games. Widespread application seems possible but research issues abound in the areas of: (1) graphic visualization design, (2) database and display algorithms, and (3) user interface requirements. Challenges include methods for rapidly displaying and changing many points, colors, and areas; multi-dimensional pointing and exploring using 6 degree of freedom input/output devices; incorporation of sound and visual display techniques that increase user comprehension; and integration with existing database systems.
(Also cross-referenced as CAR-TR-655)
(Also cross-referenced as SRC-TR-93-3)
Original paper (September 1993), revised (January 1994)
Keywords: HCIL, UNIX, Empirical Evaluation, Design, Emplementation
UNIX Notices (UN) was developed to study the problems in providing advice to users of complex systems. The issues studied were: what, when, and how to present the advice.
The first experiment with 24 subjects examined how different presentation styles affect the effectiveness of UNÕs advice. The three presentation styles studied were: notice appears in separate window; notice appears only on request; notice appears in userÕs window immediately. The results showed that the third style was significantly more effective than the first style. Furthermore, the results indicated that the most effective presentation method is also the most disruptive.
The second experiment with 29 subjects studied how delay in the advice feedback affects the performance of UN. The treatments were: immediate feedback, feedback at end of session, and no feedback. Over a period of 6 weeks, the commands entered by the subjects were logged and studied. The results showed that immediate feedback caused subjects to repeat significantly fewer inefficient command sequences. However, immediate feedback and feedback at end of session may have given subjects a negative feeling towards UNIX.
(Also cross-referenced as CAR-TR-651)
Keywords: Menus, User interface, Human-computer interaction, selection frequency,, Split menus
When some items in a menu are selected more frequently than others, as is often the case, designers or individual users may be able to speed performance and improve satisfaction by placing several high-frequency items at the top of the menu. Design guidelines for split menus were developed and applied. Split menus were implemented and tested in two field studies and a controlled experiment. In the field study conditions performance times were reduced from 17 or 58% depending on the site and menus. In the controlled experiment split menus were significantly faster than alphabetic menus and yielded significantly higher subjective preferences. A possible resolution to the continuing debate among cognitive theorists about predicting menu selection times is offered. We conjecture and offer evidence that the logarithmic model applies to familiar (high-frequency) items and the linear model applies to unfamiliar (low-frequency) items.
(Also cross-referenced as CAR-TR-649)
ACM Transactions on Computer-Human Interaction, vol. 1, #1 (March 1994) 27-51 %I Human Computer Interaction Laboratory
Keywords: Treemaps, Visualization, Stock, queries
Treemap visualization techniques are extended and applied to stock market portfolios via a prototype application. Designed to facilitate financial decision-making, the prototype provides an overview of large amounts of hierarchical financial data and allows users to alter aspects of the visual display dynamically. Treemap concepts are illustrated via examples which address common portfolio management needs.
(Also cross-referenced as CAR-TR-648)
(Also cross-referenced as SRC-TR-92-120)
Keywords: HCIL, Browser, Experiment, Intermediate View
The browsing of two dimensional images can be found in a large number of applications. When the image to be viewed is much larger than the screen available, a two dimensional browser has to be provided to allow users to access all parts of the image. We show the diversity of tasks and systems available and the need for 2D browser design guidelines. In the context of a microscope image browser, we investigate one common technique consisting of a global view of the whole image, coupled to a detailed, magnified view of part of the image. In particular we look at the benefits of providing an intermediate view when the detail-to-overview ratio is high. An experiment showed that users performance significantly degrades when no intermediate view is provided for a detail-to-overview ratio over 20:1. Our experience is also a good example of a real world application for which added features and added hardware need to be justified.
(Also cross-referenced as CAR-TR-645)
(Also cross-referenced as ISR-TR-92-119)
Keywords: Speach, Mouse Command, Word Processing, HCIL
Despite advances in speech technology, human factors research since the late 1970s has provided only weak evidence that automatic speech recognition devices are superior to conventional input devices such as keyboards and mice. However, recent studies indicate that there may be advantages to providing an additional input channel based on speech input to supplement the more common input modes. Recently the authors conducted an experiment to demonstrate the advantages of using speech-activated commands over mouse-activated commands for word processing applications when, in both cases, the keyboard is used for text entry and the mouse for direct manipulation. Sixteen experimental subjects, all professionals and all but one novice users of speech input, performed four simple word processing tasks using both input groups in this counterbalanced experiment. Performance times for all tasks were significantly faster when using speech to activate commands as opposed to using the mouse. On average, the reduction in task time due to using speech was 18.67%. The error rates due to subject mistakes were roughly the same for both input groups, and recognition errors, averaged over all the tasks, occurred for 6.25% of the speech-activated commands. Subjects made significantly more memorization errors when using speech as compared with the mouse for command activation. Overall, the subjects reacted positively to using speech input and preferred it over the mouse for command activation, however, they also voiced concerns about recognition accuracy, the interference of background noise, inadequate feedback and slow response time. The authors believe that the results of the experiment provide guidance for implementors and evidence for the utility of speech input for command activation in application programs.
(Also cross-referenced as CAR-TR-630)
(Also cross-referenced as SRC-TR-92-86)
Keywords: HCIL, Boolean Queries, Graphical Representation, Filter Representation, Flow Representation
One of the powerful applications of Boolean expression is to allow users to extract relevant information from a database. Unfortunately, previous research has shown that users have difficulty specifying Boolean queries. In an attempt to overcome this limitation, a graphical Filter/Flow representation of Boolean queries was designed to provide users with an interface that visually conveys the meaning of the Boolean operators (AND, OR and NOT). This was accomplished by implementing a graphical interface prototype that uses the metaphor of water flowing through filters. Twenty subjects with no experience with Boolean logic participated in an experiment comparing the Boolean operations represented in the Filter/Flow interface with a text-only SQL interface. The subjects independently performed five comprehension tasks and five composition tasks in each of the interfaces. A significant difference (p < 0.05) in the total number of correct queries in each of the comprehension and composition tasks was found favoring Filter/Flow.
(Also cross-referenced as CAR-TR-627)
Keywords: Treemap, HCIL, Visualization, Hierarchies
Controlled experiments with novice treemap users and real data highlight the strengths of treemaps and provide direction for improvement. Issues discussed include experimental results, layout algorithms, nesting offsets, labeling, animation and small multiple displays. Treemaps prove to be a potent tool for hierarchy display. The principles discussed are applicable to many information visualization situations.
(Also cross-referenced as CAR-TR-626)
(Also cross-referenced as ISR-TR-92-62)
Keywords: HCIL, Telepathology, User Interface, Time Delays, Effects
Telepathology enables a pathologist to examine physically distant tissue samples by microscope operation over a communication link. Communication links can impose time delays which cause difficulties in controlling the remote device. Such difficulties were found in a microscope teleoperation system. Since the user interface is critical to pathologist's acceptance of telepathology, we redesigned the user interface for this system, built two different versions (a keypad whose movement commands operated by specifying a start command followed by a stop command and a trackball interface whose movement commands were incremental and directly proportional to the rotation of the trackball). We then conducted a pilot study to determine the effect of time delays on the new user interfaces. In our experiment, the keypad was the faster interface when the time delay is short. There was no evidence to favor either the keypad or trackball when the time delay was longer. Moving long distances over the microscope slide by dragging the field-of-view indicator on the touchscreen control panel improved inexperienced user performance. Also, the experiment suggests that changes could be made to improve the trackball interface.
(Also cross-referenced as CAR-TR-616)
(Also cross-referenced as SRC-TR-92-49)
Keywords: hypertext database structure, hyperspace, navigation, hierarchization, cluster, metrics, tree-maps, fisheye views
Analyzing the structure of a hypertext database can give useful information to the traveler in hyperspace. We present a preliminary collection of structural tools for users of hypertext systems. These tools can suggest answers to questions like: Where am I ? How can I choose and get to my destination? What else is in my current neighborhood? etc. Structure is imposed on the hypertext by using two processes: hierarchization and cluster identification. Several metrics are presented and used in the above processes for locating landmarks and getting global information on the hypertext structure. The structural analysis is integrated with previous attempts to reduce the users' disorientation while navigating the hyperspace. An integration with fisheye views and tree-maps is presented.
(Also cross-referenced as CAR-TR-606)
Keywords: HCIL, Browsing, Dynamic Queries, Information Display Techniques
We designed, implemented, and evaluated an innovative concept for dynamic queries which involves the direct manipulation of small databases. Our domain was directories in a Unix file system. Dynamic queries allow users to formulate queries and explore the databases with graphical widgets, such as sliders and buttons, without requiring them to have any knowledge about the underlying structure of the database query languages, or command language syntax. Three interfaces for presenting directories were developed and tested with eighteen subjects in a within-subject design. The results of the formative evaluation yielded some useful guidelines for software designers.
(Also cross-referenced as CAR-TR-605)
Keywords: Layout Appropriateness, Evaluating user interfaces, User interfaces, Widget, Metric, HCIL
Numerous methods to evaluate user interfaces have been investigated. These methods vary greatly in the attention paid to the usersÕ tasks. Some methods require detailed task descriptions while others are task-independent. Unfortunately, collecting detailed task information can be difficult. On the other hand, task-independent methods cannot evaluate a design for the tasks users actually perform. The goal of this research is to develop a metric, which incorporates simple task descriptions, that can assist designers in organizing widgets in the user interface. Simple task descriptions provide some of the benefits, without the difficulties, of performing a detailed task analysis. The metric, Layout Appropriateness (LA), requires a description of the sequences of widget-level actions users perform and how frequently each sequence is used. This task description can either be from observations of an existing system or from a simplified task analysis. The appropriateness of a given layout is computed by weighting the cost of each sequence of actions by how frequently the sequence is performed. This emphasizes frequent methods of accomplishing tasks while incorporating less frequent methods in the design. Currently costs are based on the distance users must move the mouse. Other measures such as the number of eye fixations necessary to extract the relevant information or measure like the number of changes in direction may also prove useful, but must be validated before they are made available for use. In addition to providing an comparison of a proposed or existing layouts, an LA-optimal layout is presented to the designer. The designer can compare the LA-optimal and existing layouts or start with the LA-optimal layout and modify it to take additional factors into consideration. Software engineers who occasionally face interface design problems and user interface designers can benefit from the explicit focus on the usersÕ tasks that LA incorporates into automated user interface evaluation.
(Also cross-referenced as CAR-TR-603)
Keywords: HCIL, Dynamic HomeFinder, Dynamic Queries, Information Exploration,, Real-Estate
We designed, implemented, and evaluated a new concept for visualizing and searching databases utilizing direct manipulation called dynamic queries. Dynamic queries allow users to formulate queries by adjusting graphical widgets, such as sliders, and see the results immediately. By providing a graphical visualization of the database and search results, users can find trends and exceptions easily. User testing was done with eighteen undergraduate students who performed significantly faster using a dynamic queries interface compared to both a natural language system and paper printouts. The interfaces were used to explore a real-estate database and find homes meeting specific search criteria.
(Also cross-referenced as CAR-TR-602)
Keywords: HCIL, Information Visualization, Multi-attribute listing,, multi-attribute table
The "value bar" provides an overview of a large listing with multiple, quantifiable attributes. Value bars are a cross between scrollbars and space efficient stacked bar charts. A space-filling algorithm assigns relatively sized regions in the value bar according to items' attribute values. In a glance users can discern the distribution of attribute values of the entire listing. Navigation features provide quick identification and in-context fisheye views of listing items. Many value bars can be created to compare distributions of the same items over different attributes. A usability study showed value bars are easy to use and understand. Value bars can be added to applications involving directory listings, databases and their search results, tables of contents, stock market tables, medical information, etc.
(Also cross-referenced as CAR-TR-589)
Keywords: Touchscreen, Interfaces, data entry, alphanumeric, HCIL
Touchscreens have been demonstrated as useful for many applications. Although a traditional mechanical keyboard is the device of choice when entering alphanumeric data, it may not be optimal when only limited data must be entered, or when the keyboard layout, character set, or size may be changed. A series of experiments has demonstrated the usability of touchscreen keyboards. The first study indicated that users who type 58 wpm on a traditional keyboard can type 25 wpm using a touchscreen and that the traditional monitor position is suboptimal for touchscreen use. A second study reported on typing rates for keyboards of various sizes (from 6.8 to 24.6 cm wide). Novices typed approximately 10 wpm on the smallest and 20 wpm on the largest of the keyboards. Users experienced with touchscreen keyboards typed 21wpm on the smallest and 32 wpm on the largest. We then report on a recent study done with more representative users and more difficult tasks. Thirteen cashiers were recruited for this study and were required to complete ten trials in which they typed names and addresses with punctuation. Results indicate that the users improved rapidly from 9.5 wpm on the first trial to 13.8 wpm on the last trial, reaching their fastest performance after only 25 minutes. Although custom interfaces will be preferred for special types of data (e.g. telephone numbers, times, dates, colors) there will always be situations when limited quantities of text must be entered. In these situations a touchscreen keyboard can be used.
(Also cross-referenced as CAR-TR-585)
Keywords: HCIL, Dynamic Queries, Information Exploration, Implementation, Evaluation
We designed, implemented and evaluated a new concept for direct manipulation of databases, called dynamic queries, that allows users to formulate queries with graphical widgets, such as sliders. By providing a graphical visualization of the database and search results, users can find trends and exceptions easily. Eighteen undergraduate chemistry students performed statistically significantly faster using a dynamic queries interface compared to two interfaces both providing form fill-in as input method, one with graphical visualization output and one with all-textual output. The interfaces were used to expore the periodic table of elements and search on their properties.
(Also cross-referenced as CAR-TR-584)
Keywords: HCIL, User Interface, Visual, Information Exploration
The next generation of database management, directory browsing, information retrieval, hypermedia, scientific data management, and library systems can enable convenient exploration of growing information spaces by a wider range of users. User interface designers can provide more powerful search techniques, more comprehensible query facilities, better presentation methods, and smoother integration of technology with task. This paper offers novel graphical and direct manipulation approaches to query formulation and information presentation/manipulation. These approaches include a graphical approach to restricted boolean query formulation based on generalization/aggregation hierarchies, a filter/flow metaphor for complete boolean expressions, dynamic query methods with continuous visual presentation of results as the query is changed (possibly employing parallel computation), and color-coded 2-dimensional space-filling tree-maps that present multiple-level hierarchies in a single display (hundreds of directories and more than a thousand files can be seen at once).
(Also cross-referenced as CAR-TR-577)
Keywords: HCIL, Graphical User Interface, Visual queries, Aggregation/Generalization Hierarchies, Empirical Test
In order for automated information systems to be used effectively, they must be made easily accessible to a wide range of users and with short training periods. This work proposes a method of organizing documents based on the concepts of aggregation and generalization hierarchies. We propose a graphical user interface to provide a more intuitive form of Boolean query. This design is based on mapping the nodes of the aggregation hierarchy to Boolean intersection operations, mapping the nodes of the generalization hierarchy to Boolean union operations, and providing a concrete, graphical, manipulable representation of both of these node types. Finally, a working prototype interface was constructed and evaluated experimentally against a classical command-line Boolean query interface. In this formative evaluation with sixteen subjects, the graphical interface produced less than one-tenth the errors of the textual interface, on average. Significant differences in time spent specifying queries were not found. Observations and comments provide guidance for designers.
(Also cross-referenced as CAR-TR-562)
Keywords: Touchscreen, Effect of Keyboard Size, Typing speed, HCIL
Two studies investigated the effect keyboard size has on typing speed and error rates for touchscreen keyboards using the lift-off strategy. A cursor appeared when users touched the screen and a key was selected when they lifted their finger from the screen. Four keyboard sizes were investigated ranging from 24.6 cm to 6.8 cm wide. Results indicate that novices can type approximately 10 words per minute (WPM) on the smallest keyboard and 20 WPM on the largest. Experienced users improved to 21 WPM on the smallest keyboard and 32 WPM on the largest. These results indicate that, although slower, small touchscreen keyboards can be used for limited data entry when the presence of a regular keyboard is not practical. Applications include portable pocket-sized or palmtop computers, messaging systems, and personal information resources. Results also suggest the increased importance of experience on these smaller keyboards. Research directions are suggested.
(Also cross-referenced as CAR-TR-553)
Keywords: Tree-Maps, Space Filling, Visualization, Hiererchical Information Structures
This paper describes a novel method for the visualization of hierarchically structured information. The Tree-Map visualization technique makes 100% use of theavailable display space, mapping the full hierarchy onto a rectangular region in a space-filling manner. This efficient use of space allows very large hierarchies to be displayed in their entirety and facilitates the presentation of semantic information.
(Also cross-referenced as CAR-TR-93-72)
Keywords: HCIL, user interface, direct manipulation, telemedicine,, remote control
This paper describes our experience with the design of a remote pathologistÔs workstation. We illustrate how our effort to apply direct manipulation principles led us to explore remote direct manipulation designs. The use of computer and communication systems to operate devices remotely introduces new challenges for users and designers. In addition to the usual concerns, the activation delays, reduced feedback, and increased potential for breakdowns mean that designers must be especially careful and creative. The user interface design is closely linked to the total system design.
(Also cross-referenced as CAR-TR-551)
Keywords: HCIL, Hypertext, Structural Analysis, Graph Theory, Abstraction, Generalization, Aggregation
Hypertext systems are being used in many applications because of their flexible structure and the great browsing freedom they give to diverse communities of users. However, this same freedom and flexibility is the cause of one of its main problem: the Òlost in hyperspaceÓ problem. One reason for the complexity of hypertext databases is the large number of nodes and links that compose them. To simplify this structure we propose that nodes and links be clustered forming more abstract structures. An abstraction is the concealment of all but relevant properties from an object or concept.
One type of abstraction is called an aggregate. An aggregate is a set of distinct concepts that taken together form a more abstract concept. For example, two legs, a trunk, two arms and a head can be aggregate together in a single higher level object called a Òbody.Ó In this paper we will study the hypertext structure, i.e., the way nodes are linked to each other in order to find aggregates in hypertext databases. Two graph theoretical algorithms will be used: biconnected components and strongly connected components.
(Also cross-referenced as CAR-TR-550)
Keywords: Tree Visualization, Tree-maps, 2-d space filling, HCIL
This paper presents a novel approach to representing trees that have weights or sizes on the leaf nodes. The 2-d visualization is space filling and the recursive algorithm for generation runs rapidly. It depends on color coding (or shading) of regions and easily provides users with a quick overview that clearly indicates relative sizes of the leaf nodes. Figures 3 & 4 show examples of tree-maps with size coding, as implemented by Brian Johnson on a Apple Macintosh II computer with a high resolution color display. Figure 3 shows fifteen files in four directories at three levels, with nested boxes to show the levels. Figure 4 represents actual disk directories encompassing 850 files at four levels with color coding by file type (text, graphics, applications, etc). We continue to explore refinements of tree-maps such as alternate layouts, better methods for coping with large ranges of file size, color coding schemes, and operations applied to files.
(Also cross-referenced as CAR-TR-548)
Keywords: HCIL, Browsing, Hierarchies, Tables of Contents, User Interfaces,
Three different interfaces were used to browse a large (1296 items) table of contents. A fully expanded stable interface, expand/contract interface, and multi-pane interface were studied in a between-groups experiment with 41 novice participants. Nine timed fact retrieval tasks were performed, each task is analyzed and discussed separately. We found that both the expand/contract and multi-pane interfaces produced significantly faster times than the stable interface for many tasks using this large hierarchy; other advantages of the expand/contract and multi-pane interfaces over the stable interface are discussed. The animation characteristics of the expand/contract interface appear to play a major role. Refinements to the multi-pane and expand/contract interfaces are suggested. A predictive model for measuring navigation effort of each interface is presented.
(Also cross-referenced as CAR-TR-539)
Keywords: hypertext, hyperspace, authoring tools, hierarchy, links, navigate, database structure analysis, user interface design, metrics
In hypertext databases users often suffer from the well known problem of getting "lost in hyperspace." An approach to solve this problem consists of improving authoring. This paper proposes several authoring tools, based on database structure analysis.
In many hypertext systems authors are encouraged to create hierarchical structures, but when writing, the hierarchy is lost because of the inclusion of cross-reference links. The first part of this paper will look at ways of recovering lost hierarchies and finding new ones, offering authors different views of the same database. The second part helps authors by identifying properties of the database. Multilple metrics are developed: among them the compactness and stratum. The compactness indicates the intrinsic complexity of the databse and the stratum reveals to what degree the database is organized so that some nodes should be read before others.
Several from existing databases are used to illustrate the benefits of each tool. The collection of these tools provides a multifaceted view of the database and should allow authors to identify weaknesses in their database's structure and create better documents which users will be able to traverse more easily.
(Also cross-referenced as CAR-TR-526)
Keywords: HCIL, Archaeology, hypertext system, museum
This case study shows how a hypertext system was used in a traveling exhibit of the Smithsonian Institution. The database about archaeology was constructed by a professor and students of the history department of the University of Maryland. Regular updates of the database were made for each new venue of the exhibit. Finally the database was translated into French and automatically rebuilt to be used in Canada. Helpful features of the hypertext system as well as the difficulties encountered are described. System users were observed in the museum and collected usage data was analyzed.
(Also cross-referenced as CAR-TR-523)
Keywords: HCIL, Touchscreen, Keyboards
This study explored touchscreen keyboards using high precision touchscreen strategies. Phase one evaluated three possible monitor positions: 30, 45, and 75 degrees from horizontal. Results indicate that the 75 degree angle, approximately the standard monitor position, resulted in more fatigue and lower preference ratings. Phase two collected touch bias and key size data for the 30 degree angle. Subjects consistently touched below targets, and touched to the left of targets on either side of the screen. Using these data, a touchscreen keyboard was designed. Phase three compared this keyboard with a mouse activated keyboard, and the standard QWERTY keyboard for typing relatively short strings of 6, 19, and 44 characters. Results indicate that users can type approximately 25 words per minute with the touchscreen keyboard, compared to 17 WPM using the mouse, and 58 WPM when using the keyboard. Possible improvements to touchscreen keyboards are suggested.
(Also cross-referenced as CAR-TR-515)
Keywords: hypertext tutorial, hyperspace, Hyperties authoring, training
This paper describes the design and evaluation of a hypertext-based tutorial for hypertext authors. This 85-article tutorial represents an innovative application of hypertext to procedural learning. The work has been guided by Carroll's minimalist model, and by the syntactic/semantic model of user behavior. The usability study involved 8 subjects who studied the Hyperties Author Tutorial (HAT) for approximately one hour and then performed a set of authoring tasks in an average of 21 minutes. All users successfully completed the tasks. As a result of the study, we provide a characterization of appropriate uses of hypertext for training, and describe the meaning of a hyper-active environment.
(Also cross-referenced as CAR-TR-509)
Keywords: high-precision touchscreens, direct manipulation, graphical user interface
While many input devices allow interfaces to be customized, increased directness distinguishes touchscreens. Touchscreens are easy to learn to use, fast, and result in low error rates when interfaces are designed carefully. Many actions which are difficult with a mouse, joystick, or keyboard are simple when using a touchscreen. Making rapid selections at widely separated locations on the screen, signing your name, dragging the hands of a clock in a circular motion are all simple when using a touchscreen, but may be awkward using other devices. This paper presents recent empirical research which can provide a basis for theories of touchscreen usage. We believe recent improvements warrant increased use of touchscreens.
(Also cross-referenced as CAR-TR-506)
Keywords: HCIL, browsing, hyperties, workstation browser
Since browsing hypertext can present a formidable cognitive challenge, user interface design plays a major role in determining acceptability. In the Unix workstation version of Hyperties, a research-oriented prototype, we focussed on design features that facilitate browsing. We first give a general overview of Hyperties and its markup language. Customizable documents can be generated by the conditional text feature that enables dynamic and selective display of text and graphics. In addition we present: - an innovative solution to link identification: pop-out graphical buttons of arbitrary shape. - application of pie menus to permit low cognitive load actions that reduce the distraction of common actions, such as page turning or window selection. - multiple window selection strategies that reduce clutter and housekeeping effort. We preferred piles-of-tiles, in which standard-sized windows were arranged in a consistent pattern on the display and actions could be done rapidly, allowing users to concentrate on the contents.
(Also cross-referenced as CAR-TR-494)
Keywords: database structure, tree diagrams, hierarchical, spatial visualization, navigation, training
Users need instructions about the structure of a data base and about what commands are available for use in menu traversal. Early research has shown that subjects who received tree diagrams of a data base were most successful in searching a hierarchical data base. Later research demonstrated that subjects who studied information presented in the form of an analogy performed better than did subjects who studied a tree diagram. Considering work by Vicente, Hayes and Williges, the present experiment attempted to show that spatial visualization ability can be used to determine what form of instruction results in a difference in performance very early in the use of a data base. Subjects were grouped according to their spatial visualization ability and were randomly assigned to one of four study conditions. Subjects studied either a tree diagram of the data base of college courses, an analogy describing the structure of the data base, both the analogy and the tree diagram, or nothing about the data base. Results replicated the finding that studying a tree diagram results in the best performance among the four methods of study. Furthermore, high spatial visualization subjects made fewer moves and took less time to find targets than did low spatial visualization subjects. However, results provided no support for accelerated learning when subjects were provided with materials that complemented their spatial visualization ability.
(Also cross-referenced as CAR-TR-488)
Keywords: hypertext databases, window control strategies, tiled windows, navigation
Nowadays, larger and higher resolution screens supporting multiple windows are widely available. They are often used to traverse hypertext databases for fact retrieval, education or casual browsing. This paper describes a study comparing two methods of window control strategies for article placement in four, equal sized and tiled windows (By tiled we mean non-overlapping, non-movable and non-resizable windows, which together cover the entire screen.) The first placement strategy - Automatic Panning (AP) - was controlled by the system software and the second placement strategy - User Controlled Placement (UCP) - transferred control to the users. The task required subjects to answer questions about the content of a hypertext. Statistical analysis shows that subjective preference was significantly higher and amount of backtracking was significantly lower for the user controlled placement. Speed differences did not prove to be significant, although there was consistent tendency favoring the automatic panning strategy.
(Also cross-referenced as CAR-TR-475)
Keywords: Window Strategies Environment developer tool, object oriented methodology, Smalltalk
This paper describes Window Strategies Environment (WSE), which is an environment for exploring different window strategies. It is a tool for developers who want to implement and explore different window strategies easily. WSE uses object oriented methodology offering four hierarchical levels for customizing predefined window strategies. The highest level is a simple modifiable language for describing a few essential commands for each strategy.
This kind of tool helps the developers to implement and test several approaches to window strategies before selecting one. Also it encourages the developer to direct some of the power to the user so that she can customize the user interface by selecting a preferred strategy from a predefined set of strategies.
The environment is implemented under NeWS 1/1 [Sun87] window system for SUN 4/110. It uses Smalltalk style object oriented class mechanisms [Golberg83, Densmore] offered by NeWS but none of the original NeWS toolkits.
(Also cross-referenced as CAR-TR-473)
Keywords: HCIL, touchscreen, home control, scheduling, usability evaluation
This article describes four different user interfaces supporting scheduling two state (ON/OFF) devices over time periods ranging from minutes to days. The touchscreen-based user interfaces including a digital, 12-hour clock, 24-hour linear and 24-hour dial prototypes are described and compared on a feature by feature basis. An informal usability test with 14 subjects, feedback from more than 30 reviewers, and the flexibility to add functions favors the 24-hour linear version.
(Also cross-referenced as CAR-TR-472)
Keywords: HCIL, Touchscrean, High Precision, Mouse
Three studies were conducted comparing speed of performance, error rates, and user preference ratings for three selection devices. The devices tested were a touchscreen, a touchscreen with stabilization (stabilization software filters and smooths raw data from hardware), and a mouse. The task was the selection of rectangular targets 1, 4, 16, and 32 pixels per side (0.4x0.6, 1.7x2.2, 6.9x9.0, 13.8x17.9 mm respectively). Touchscreen users were able to point at single pixel targets, thereby countering widespread expectations of poor touchscreen resolution. The results show no difference in performance between the mouse and touchscreen for targets ranging from 32 to 4 pixels per side. In addition, stabilization significantly reduced the error rates for the touchscreen when selecting small targets. These results imply that touchscreens, when properly used, have attractive advantages in selecting targets as small as 4 pixels per size (approximately one-quarter of the size of a single character). A variant of Fitts' Law is proposed to predict touchscreen pointing times. Ideas for future research are also presented.
(Also cross-referenced as CAR-TR-450)
Keywords: hypertext system design, visual display, direct manipulation, graphical user interface, layout appropriateness
One of the key design aspects of hypertext systems is the rapid selection of items displayed on the screen in a direct manipulation manner. The user can select next or back page turning icons or buttons, or select another item that might jump to a remote destination. Authors and browsers are confronted with the problem of recognizing and selecting these choices in textual and graphic databases. This paper discusses the problems and offers a variety of solutions.
(Also cross-referenced as CAR-TR-449)
Keywords: HCIL, Hypertext System, User Interface, Signature file,, String Serch
Hypertext systems provide an appealing mechanism for informally browsing databases by traversing selectable links. However, in many fact finding situations string search is an effective complement to browsing. This paper describes the application of the signature file method to achieve rapid and convenient string search in small personal computer hypertext environments. The method has been implemented in a prototype, as well as in a commercial product. Performance data for search times and storage space are presented from a commercial hypertext database. User interface issues are then discussed. Experience with the string search interface indicates that it was used sucessfully by novice users.
(Also cross-referenced as CAR-TR-448)
Keywords: automatic hypertext conversion, document markup,, link structures
We describe our experiences with four separate conversions from paper documents into hypertext and discuss the lessons we have learned. The paper document's organization affects the ease with which it can be converted and the appropriateness of the resulting hypertext. The form of the paper document's machine-readable 'markup' description affects the ability to transform the structure automatically. Designing the link structures that tie together the parts of the hypertext takes special care in automating, as badly-designed and incorrectly-formed links destroy the integrity of the hypertext. Overall, each of the conversions followed the same basic methodology, providing the handle for the development of 'power tools' that can be applied to simplify subsequent conversions.
(Also cross-referenced as CAR-TR-443)
Keywords: UNIX, intelleigent interfaces, system design, user interfaces, spell checkers, filter testing methods
A UNIX shell (csh) was modified to automatically correct misspelled command lines. The design and implementation were not easy, contrary to the opinions of previous researchers. After implementation, the shell was given to 21 users for evaluation. Their comments and performance suggest that any change to a familiar system may overshadow potential benefits of a new system. Designers of spelling correctors must be extremely cautious in order to produce a satisfactory system. Minimal distraction from the user's task should be a prime goal in designers of correction facilities. Spelling corrector filters and methods of testing filters are discussed.
(Also cross-referenced as CAR-TR-440)
Keywords: user interfaces, windowing systems, hypertext, browsing systems
The program browsing problem is discussed, with particular emphasis on a multiple-window user interface and its implications for recording acquired knowledge, navigation, and attention-tracking. Hypertext systems are considered as an implementation of browsing techniques for non-program text. A classification scheme for text-viewing systems is offered, and then browsing is discussed as a non-intrusive, static technique for program study.
Multiple techniques are synthesized into a coherent plan for a multi- window program study tool, based on theories of program browsing and the use o hypertext. A test system, HYBROW, emerged from the plan for studying the application of several hypertext multiple-window techniques to program browsing, especially window replacement. HYBROW is a hypertext, multiple- window program browser. This generic tool is applicable to any source language, although certain aspects of the preprocessing and the hierarchical browser presentation are specific to the C language. The tool permits opening an arbitrary number of text windows into an arbitrary number of files, rapid window switching, multiple-window search, place-marking, automatic screen organization, and services for the creation, maintenance and production of study notes. An informal usability study was conducted.
(Also cross-referenced as CAR-TR-437)
Keywords: HCIL, directions
This paper offers a set of goals for user interface development and then scenarios of future developments. The applications include home control, hypermedia, office automation, digital photography, collaborative meeting/classrooms, public access, professional workstations, and medical record-keeping. Also, predictions are made for some of the underlying technologies such as User Interface Management Systems, remote control, flexible search, display devices, and touchscreens.
(Also cross-referenced as CAR-TR-436)
Keywords: hierarchical search patterns, bar-graph displays, frequency count, normalized probabilities, spatial visualization ability, search behavior
Subjects searched a simple three level hierarchical filing system to locate hypothetical documents. Search was guided only by a numerical index. The index was either (a) the probability that the document would be found by selecting one of the alternatives, (b) a frequency count of possible hits available by selecting one of the alternatives, or (c) a bar-graph of the likelihood that each of the alternatives would lead to the target document. The three indices were calculated using either (a) joint probabilities or (b) probabilities normalized across the alternatives at each level. An analysis of search patterns indicated that subjects tended to follow highest probabilit paths for the first traversal. If the target was not found, they engaged in a local search at the bottom of the hierarchy. If the target was still not found, they attempted to follow the second highest probability path down. Results indicated that subjects made the fewest deviations from the best path when probabilities were normalized. Furthermore, bar-graph displays uniformly resulted in the fewest deviations from the best path. When subjects redirected their search, they could either move up the hierarchy one level or restart at the top. Subjects with high spatial visualization ability were more likely to move up one level, while subjects with low spatial visualization were more likely to restart the search. Finally, if the target was not found after several attempts, search patterns began to reveal considerable redundant random search behavior and checking of paths. Techniques are suggested to reduce inefficient search patterns.
(Also cross-referenced as CAR-TR-432)
Keywords: HCIL, hypertex, authoring, editing, managing
This chapter offers recommendations for potential authors of hypertext documents based on the experience of designing a hypertext system and of creating a series of substantial hypertext databases on personal computers and larger workstations. Advice on choosing projects, identifying useful author tool features, and structuring knowledge is presented. Additional issues such as the design of the root document, article size, and conversion from existing databases are covered. While hypertext has exciting potentials, the dangers of poor design must be overcome to create attractive and effective products.
(Also cross-referenced as CAR-TR-410)
Keywords: High resolution touch screens, Hyperties, hypertext
High resolution touch screens and novel usage strategies have overcome earlier problems with parallax and inaccurate pointing. A study testing the utility of three touch screen strategies within the Hyperties hypertext environment was performed. This provided a replication and extension of an earlier touch screen strategy comparison that focused on small closely-spaced targets. The experiment compared three touch screen strategies in three experimental tasks that reflect hypertext usage. The results showed that a strategy that only uses the initial impact with the touch screen causes the user to miss the target more than other touch strategies. A statistically significant difference in errors was found. Our results should encourage system implementers and touch screen hardware designers to support "touch mouse" strategies that enable coursor dragging on the touch screen surface.
(Also cross- referenced as CAR-TR-405)
Keywords: User adaptable, menu, linking
Creation and traversal of links in a user adaptable menu was examined for syntagmatically and paradigmatically related targets. One group searched for paradigmatic related targets within the same intermediate category under different superordinate categories, while another searched for syntagmatic related targets belonging to different intermediate catgories under the same superordinate. Users with syntagmatic targets created and traversed more superordinate category links, while users with paradigmatic targets traversed more intermediate category links. As predicted, more horizontal links at the same hierarchical level were created and traversed than diagonal links joining different levels. Overall, users tended to create links forming hierarchical networks.
(Also cross- referenced as CAR-TR-396)
Keywords: Menu Selection Prototyping System (MSPS), users guide
This report provides an overview of the Menu Selection Prototyping System (MSPS) written for use in research on menu selection in the Human/Computer Interaction Laboratory at the University of Maryland. In addition, a users guide is provided to assist researchers on the development of experimental menu selection systems and use of the program. The MSPS is a general program for the MS-DOS environment that is capable of driving any type of menu architecture and recording user selections and response times.
(Also cross-referenced as CAR-TR-393)
Keywords: home automation system, American Voice and Robotics (AVR), interface usability testing
American Voice and Robotics (AVR), in conjunction with the Maryland Industrial Partnerships (MIPS) program, contracted the Human-Computer Interaction Laboratory (HCIL) to evaluate the user interface of AVRÕs ÒGuardianÓ home automation system. Among their goals for the system were: Ease of use and learning of the system (intuitiveness). Aesthetic appeal, Unintimidating, Impressive, High Functionality, Fast and accurate input of user action, Clear feedback, Forgiving to errors, and Fun to use. Researchers found that users were initially impressed with the system, but that they were not fully satisfied with it. Specific initial recommendations, theoretical and methodological concerns, procedures, results, and direction of future research will be discussed.
(Also cross-referenced as CAR-TR-392)
Keywords: hypertext, user satisfaction, display format, search strategy, Information seeking
Information systems support problem solving and decision making. Information seeking, a special case of problem solving, ranges from fact retrieval to ongoing self instruction. The research reported here looks at the effect of a system's human interface on fact retrieval in an electronic hypertext environment . Two experiments were conducted. The first looked at the effect, on user performance, of searching electronic versus paper versions of an encyclopedia. The second examined the effect of two distinct search strategies, index use and browsing, on subject performance in the electronic version of the same encyclopedia. In addition this experiment looked at the effect of previous computer/online searching experience on performance. Results indicate that subjects complete searches faster using paper, but that search success was the same for both print and electronic versions. Use of an index as a search strategy proved more efficient overall than a browse strategy in terms of search success and other dependent measures. However, superiority of the index strategy diminished over several searches and for some performance measured reversed, indicating a possible learning effect. Previous computer/online searching experience did not have a significant effect on subject performance.
(Also cross-referenced as CAR-TR-353)
Keywords: menu selection, metaphor, user models, human-computer interaction
Menu selection in human/computer interaction is a metaphor of the restaurant menu. Although menu selection is widely used, its scope is currently limited, narrow, and information lean. A comparison of the restaurant menu and the computer menu reveal the following: The correspondence of elements and features between restaurant and computer menus suggests a powerful metaphor. Second, there are a number of advantages of dynamic computer menus over static listings common to restaurants. Finally, restaurant menus have the advantage of breadth, richness, and graphic layout as well as a system of support ( the server) that is unparalleled in current computer applications. An analysis of deficiencies in computer menus should prove invaluable in developing the next generation of menu selection techniques.
Keywords: user satisfaction, user interface quesitonnaire, design tool
This study is part of a research effort to develop the Questionnaire for User Interface Satisfaction (QUIS). Participants, 150 PC user group members, rated familiar software products. Two pairs of software categories were compared: 1) software that was liked and disliked, and 2) a standard command line system (CLS) and a menu driven application (MDA). The reliability of the questionnaire was high, Cronback's alpha=.94. The overall reaction ratings yielded significantly higher ratings for liked sof tware and MDA over disliked software and a CLS, respectively. Frequent and sophisticated PC users rated MDA more satisfying, powerful and flexible than CLS. Future applications of the QUIS on computers are discussed.
Also cross-referenced as CAR-TR-328
Keywords: menus, user interface, empirical studies, directional selection
Menus are largely formatted in a linear fashion listing items from the top to bottom of the screen or window. Pull down menus are a common example of this format. Bitmapped computer displays, however, allow greater freedom in the placement, font, and general presentation of menus. A pie menu is a format where the items are placed along the circumference of a circle at equal radial distances from the center. Pie menus gain over traditional linear menus by reducing target seek time, lowering error rates by fixing the distance factor and increasing the target size in Fitts's Law, minimizing the drift distance after target selection, and are, in general, subjectively equivalent to the linear style.
Keywords: interface design, human-computer interaction,, selection devices, touch screen
This study measured the speed, error rates, and subjective evaluation of arrow-jump keys, a jump-mouse, number keys, and a touch screen in an interactive encyclopedia. A summary of previous studies comparing selection devices and strategies is presented to provide the background for this study. We found the touch screen to be the fastest in time, the least accurate, but the overall favorite of the participants. The results are discussed and improvements are suggested accordingly.
(Also cross referenced as CAR-TR-321)
Keywords: interface design, human-computer interaction,, programming environments
This study investigated subjective evaluations of two programming environments: 1) SUPPORT, an interactive programming environment with a syntax directed editor on a personal computer and 2) a batch run environment on a large mainframe computer. Participants were students in a 15 week introductory computer science course. In Part 1, one group of 128 first used SUPPORT, while another group of 85 programmed on a mainframe environment. After 6 weeks they were given an evaluative questionnaire and then switched programming environments. In Part 2, 68 used SUPPORT and 60 used the mainframe. At the twelfth week of the course, they were given two questionnaires, one evaluating the environment they had used in the last 6 weeks and one comparing both environments. A measure of programming performance (exam and programming project grades) was also collected. SUPPORT was predicted to reduce the burden of remembering syntactic details resulting in better performance and higher subjective evaluations. Unexpectedly, the SUPPORT users did not earn statistically significantly higher grades. Furthermore, participants expressed a preference for the mainframe over SUPPORT. Specific items on the questionnaires were used to diagnose the strengths and weaknesses of each environment. Designers of syntax directed editors should focus on reducing the syntactic burden not only in programming , but also in the user interface of these tools.
(Also crossed referenced as CAR-TR-304)
Keywords: interface design, human-computer interaction,, menu system commands
Hierarchical menu trees can be generated by either top-down sorting, i.e. successive divisions of groups of commands into smaller subgroups, or bottom-up sorting, i.e. successive aggregation of small groups of commands into larger superordinate categories. Previous researchers have used a hybrid sorting technique employing both top- down and bottom-up procedures together. The present paper examined the effects of top-down and bottom-up sorting tasks separately. Native English speakers, 14 males and 36 females, sorted 25 Automated Teller Machine commands twice. Although sorting time for top-down and bottom-up did not differ, both tasks were performed faster with practice. Top-down and bottom-up sorting tasks were expected to result in different hierarchical trees and mental models: top-down should emphasize differences between commands, while bottom-up should favor similarities among commands being sorted. As predicted, top-down sorting created trees with a greater number of terminal nodes, while bottom-up sorting produced trees with a larger mean number of commands per terminal node. In addition, bottom-up sorting generated trees with greater breadth. Moreover, mean breadth increased for both top- down and bottom-up from the first sort to the second sort while depth decreased. Surprisingly, depth was not a factor determining the differences between top-down and bottom-up conditions. Multi- dimensional scaling solutions revealed 3 underlying polarities: 1) object vs. action oriented commands, 2) change vs. no change in account balances, and 3) possession of money. Unexpectedly, top- down and bottom-up generated mental models did not converge toward a common model from the first sort to the second sort, but tended to diverge. The results suggest that bottom-up trees are superior to top-down. These findings indicate that interface designers should utilize bottom-up sorting in hierarchical menu tree construction.
(Also crossed referenced as CAR-TR-303)
Keywords: interface design, human-computer interaction, hypertext, on-line encyclopedia
The Interactive Encyclopedia System (TIES) has been under development since Fall 1983. It enables users to easily traverse a database of articles by merely pointing at highlighted words in context. This embedded menus approach to hypertext and its user interface design are described with three exploratory studies of TIES use. Plans for future development and studies are offered.
(Also cross referenced as CAR-TR-280)
Keywords: interface design, human-computer interaction, menu selection, form fill-in, command language, natural language interaction, direct manipulation
This review focusses on five primary interaction styles: menu selection, form fill-in, command language, natural language interaction, and direct manipulation. Each style is described, some guidelines are offered, and an airlines reservation example is shown in all five styles. Then a set of IF-THEN rules are offered to help in decision making during design. This is a first attempt that is meant to provoke discussion and encourage others to offer an extended, refined, and validated set of rules.
(Also crossed referenced as CAR-TR-265)
Keywords: File Manipulation, Command, Direct Manipulation, HCIL
There are three basic interactive styles of control in human interfaces with computers: command, menu, and direct manipulation. In the past few years, these three styles have become the subject of many studies. However, few comparisons have been done between interfaces that use direct manipulation and command styles. This experiment compares file manipulation operations on the Apple Macintosh, which has a direct manipulation interface, with the IBM PC with MS-DOS, which has the command interface. After a brief training period, novices accomplished file manipulation tasks more rapidly, with fewer errors and greater satisfaction with the Apple Macintosh. Problems arising for both versions are discussed and suggestions for improvements are made.
(Also cross-referenced as CAR-TR-264)
Keywords: interface design, human-computer interaction, expert systems, rule-based systems
The emergence of production rules as a programming technique has stimulated the creation of many varieties of expert systems: adviser, consultants, intelligent computer-assisted instruction, oracles, and various decision aids. Applications have ranged from medicine, to computer system configuration, to automobile repair, to financial decision making, and to many other domains (Waterman, 1986).
Production rules have multiple variations, but the central theme is that a system consists of hundreds or thousands of IF-THEN rules and a large unstructured set of facts. If the antecedent conditions (IF part) are satisfied by the facts then the rule ÒfiresÓ and the consequents (THEN part) are carried out. Rules may be written and stored in any order. All rules whose antecedents are satisfied may fire, but the order of firing is unpredictable.
The nonsequential, nonprocedural behaviour and the random firing order are often cited as benefits that free up the programmer to make incremental changes easy. A few rules can be written and the system is quickly working, even though the refinements to make a complete system may take months or years. On the other hand, this approach is sometimes seen as chaotic, unstructured, or undisciplined by those who worry about the difficulties of debugging, error tracing, and predictability.
The unique nature of rule-based programming suggests that special techniques for designing, programming, browsing, debugging, testing, and documenting are necessary for expert systems. This chapter explores some possibliities for programmer and user interface design for expert systems.
Rule-based systems may be well suited for many programming situations, but an interactive system must have a good user interface to succeed. The simple question-and-answer dialogue style (teletype) may be inappropriate for many applications where greater visibility, user control, and user initiative is required. All rule-based systems must provide programmers with good facilities for managing the user interface or provide an exit to a more procedural language with screen manipulation facilities. Rule-based systems are quickly being reshaped to meet the demands of professional system developers. Rule bases are being integrated with data bases, computational tools, communications facilities, graphic manipulation software, etc. The blend of techniques will lead to more powerful systems that ease the programmerÕs burden and increase the quality of service to the end users.
(Also cross referenced as CAR-TR-244)
Keywords: interface design, human-computer interaction, window size, program reading
An experiment was conducted in which four window sizes (10, 22, 60 and 120 lines) were compared for their effectiveness for program reading. The largest window, in which the entire program could be seen at one time, was found significantly better, in both time to complete the reading task and the number of correct answers in the reading task. Subjects also preferred the larger windows to the smaller windows.
(Also cross referenced as CAR-TR-231)
Keywords: interface design, human-computer interaction, window size, software maintenance, program browsing, program comprehension, empirical studies
Software maintenance is an important part of a programmerÕs work and a productÕs life cycle, yet it remains one of the most troublesome of tasks. Even existing, newly developed techniques are not of much use, since only time can determine their value. Thus, instead of presenting another new maintenance tool or management technique, we focus on strategies for improving the presentation of information--specifically, on the new larger display screens.
(Also cross referenced as CAR-TR-192)
Keywords: interface design, human-computer interaction, empirical studies, programming research methods
This paper attempts to describe the varied intellectual territory that programmers work in. It offers several paths for researchers who wish to explore this territory: controlled experiments, observational or field studies, surveys, and cognitive theories. Finally, this paper suggests several important destinations for researchers: refining the use of current languages, improving present and future languages, developing special purpose languages, and improving tools and methods.
(Also cross referenced as CAR-TR-187)
Keywords: interface design, human-computer interaction, menu selection systems
Menu selection systems provide a means of selecting operations and retrieving information which requires little training and reduces the need for memorizing complex command sequences. However, a major disadvantage of many menu selection systems is that experienced users cannot traverse the menu tree significantly faster than novices. A common solution to this problem is to provide the menu selection system with a jump-ahead capability.
The purpose of this research was to evaluate two jump-ahead methods (type-ahead and direct-access). In the type-ahead method the user anticipates a selection on each of several successive menus and enters as many selections at one time as desired. In the direct- access method, each menu frame is assigned a unique name which the user must enter to locate it.
Thirty-two students were given training on an information retrieval system for college course information and were required to learn the two jump-ahead methods in a counter-balanced design. The direct-access method resulted in fewer traversals to learn the system, lower error rates, and reduced learning time. The subjective impressions, obtained from post-experiment questionnaires and oral comments indicated that the direct-access jump-ahead method was also preferred in a frequently used menu selection system.
(Also cross referenced as CAR-TR-168)
Keywords: interface design, human-computer interaction, embedded menus, jump-mouse, number keys, touch screen, interactive encyclopedia, selection devices
Menus can be categorized as either embedded or explicit. The difference between embedded and explicit menus is the context in which the menu items are presented. Explicit menus are the type of menus with which most people are familiar. They usually present a list of items from which the user can make a selection.
Embedded menus provide an alternative, where the menu items are embedded within the information being presented on the computer display. For example, if several paragraphs of text are to be displayed to the user, words or phrases within the text can be menu items that are highlighted or underlined. The user can choose one of these items by pointing to it and selecting it.
The embedded menus offer advantages over traditional menus. Embedded menus can reduce the complexity of decision making in comparison to explicit menus because the menu choices are presented within their original context. They also reduce the space required to display menus, thereby allowing more information to be presented to the user.
Initial experimental results show that embedded menus allow people to work faster than with traditional menu or command driven systems. In addition, people prefer embedded menus over other methods.
(Also cross referenced as CAR-TR-153)
Keywords: interface design, human-computer interaction, online information retrieval, database structuring, information navigation, document storage, graph search process
Two experiments were conducted to evaluate two styles of online documents. The first experiment compared paper manuals to online manuals using two different database structuring techniques - a sequential (linear) structure and a tree structure. People using the paper manuals were faster at solving problems than the people using the computer manuals. No differences were found between the linear and tree structures, or in accuracy of problem solutions. In a subjective evaluation of user preferences, the computer manuals were rated as better and more organized than the paper manuals.
The second experiment compared two methods of retrieving online information that allowed the reader to specify the attributes needed to guide the information retrieval process. The first manual recorded the attributes entered by the reader via menus, and material in the manuals not relevant to the current search was pruned from the search space. The second manual did not record the menu selections, and the readers repeatedly entered the attributes several times in order to complete the task. The manual that recorded the attributes allowed the readers to work over twice as fast and was preferred over the other manual.
A theoretical foundation is presented for the underlying online documentation used in the experiments. The userÕs traversal through the database is presented as a graph search process, using a production system.
The results of the experiments and their theoretical foundations are evaluated in terms of the impact they might have on future online document storage and retrieval systems.
(Also cross referenced as CAR-TR-133)
Keywords: interface design, human-computer interaction, window size, cognitive layout
In order to make computers easier to use and more versatile many system designers are exploring the use of multiple windows on a single screen and multiple coordinated screens in a single work station displaying linked or related information. The designers of such systems attempt to take into account the characteristics of the human user and the structure of the tasks to be performed. Central to this design issue is the way in which the user views and cognitively processes information presented in the windows or in multiple screens . This paper develops a theory of the Òcognitive layoutÓ of information presented in multiple windows or screens. It is assumed that users adopt a cognitive representation or layout of the type of information to be presented and the relationships among the window of screens and the information they contain. A number of cognitive layouts are derived from theories in cognitive psychology and are discussed in terms of the intent of the software driving the system and congruence with the cognitive processing of the information . It is hypothesized that the particular layout adopted by a user will drastically affect the userÕs understanding and expectation of events at the human-computer interface and could either greatly facilitate or frustrate the interaction. Ways of ensuring the former and avoiding the latter are discussed in terms of implementations on existing multiple-window and multiple-screen systems.
(Also cross referenced as CAR-TR-123)
Keywords: interface design, human-computer interaction, menu structure, information navigation
Novice computer users learned a content-free menu structure using one of four methods: Studying by trial and error, studying individual choice sequences, studying individual menu frames, or studying a global tree diagram. Following study, subjects searched for target items located at the bottom of the menu structure. The study-test sequence was repeated and subjects were finally asked to recall and reconstruct as much of the structure as possible. The Global Tree and Trial and Error groups found more targets, took less time, and recalled more items than the Command Sequence and Frame Groups. Results are consistent with the ideas that (1) menu items gain meaningfulness through use, (2) upper-level item familiarity is not critical to menu-based performance, and (3) acquiring a mental model of the menu is critical to performance.
Also cross referenced as CAR-TR-110
Keywords: interface design, human-computer interaction, menu selection, computer screen readability
This paper reviews empirical studies concerning the readability of information from computer screens. The review focuses on the form and physical attributes of complex, realistic displays of text material. Studies comparing paper and computer screen readability show that screens are less readable than paper. There are many potential factors that could lead to improvements in screen readability. Those explored in this review are size, width, design, and case of characters on the computer screen, the formatting of the screen, and the effects of color. In addition, a brief discussion of physiological and physical influences on readability and workstation design was included. Conclusions based on the empirical findings are offered to the designer for improving screen readability. Numerous areas for future research are pinpointed.
Also cross referenced as CAR-TR-94
Keywords: interface design, human-computer interaction, menu selection systems, computer training
Menu selection systems require a certain amount of training in order for users to remember how to access target functions. In this experiment users studied four different types of documentation before searching for target words in a content-free menu containing no meaningful relationships among terms. Documentation was presented to subjects in one of four modes of study. In the Command Mode subjects studied sequences of choices to arrive at a desired target. In the Menu Frame Mode subjects studied individual frames in the menu system. In the Global Tree Mode subjects studied a diagram of the menu tree. Finally, in the Trial and Error Mode subjects studied the menu system by actually selecting alternatives.
Although the Global Tree and Command Sequence Groups found the most target words during the test phase, the four groups did not differ significantly. On the other hand, differences in the ability to recall menu terms were significant with the command Sequence and Menu Frame Groups recalling the most terms. Furthermore, results indicated that the type of training fundamentally affected the type of information used in order to find targets. Subjects in the Command Sequence and Menu Frame Groups tended to rely on recall of menu terms. Furthermore, all groups relied heavily on memory of the menu tree except for the Command Squence Group. Results of this study are related to practical considerations for the design of menu selection systems.
(Also cross referenced as CAR-TR-69)
Keywords: interface design, human-computer interaction, menu structure, training methods, menu selection systems
Menu selection systems sometimes present learning problems for novice users. This comparison of four training methods for novice users found that the global tree diagram of the menu system was superior to command sequence and frame presentation methods, and somewhat better than trial and error. Methods were evaluated on the basis of (1) number of target nodes found, (2) mean number of selections to a target node, (3) recall of the menu structure, and (4) subjective rating of ease of learning.
(Also cross referenced as CAR-TR-110)