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Extending User Understanding of Federal Statistics in Tables. Gary Marchionini. Carol Hert. Liz Liddy. Ben Shneiderman. May 2000.
This paper describes progress toward improving user interfaces for US Federal government statistics that are presented in tables. Based on studies of user behaviors and needs related to statistical tables, we describe interfaces to assist diverse users with a range of statistical literacy to explore, find, understand, and use US Federal government statistics. (HCIL-TR-2000-08) (Also cross-referenced UMIACS-TR-2000-24) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, Human-Computer Interaction Laboratory, University of Maryland,
Universal Usability: Pushing Human-Computer Interaction Research to. Ben Shneiderman. July 1999.
"I feel... an ardent desire to see knowledge so disseminated through the mass of mankind that it may...reach even the extremes of society: beggars and kings." -- Thomas Jefferson, Reply to American Philosophical Society, 1808 In a fair society, all individuals would have equal opportunity to participate in, or benefit from, the use of computer resources regardless of race, sex, religion, age, disability, national origin or other such similar factors. -- ACM Code of Ethics Position Paper for National Science Foundation & European Commission meeting on human-computer interaction research agenda, June 1-4, 1999, Toulouse, France. To be published in book form. Also cross-referenced as UMIACS-TR-99-17 University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, Human-Computer Interaction Laboratory, University of Maryland,
Supporting Creativity with Advanced Information-Abundant User. Ben Shneiderman. June 1999.
A challenge for human-computer interaction researchers and user interface designers is to construct information technologies that support creativity. This ambitious goal can be attained if designers build on an adequate understanding of creative processes. This paper describes a model of creativity, the four-phase genex framework for generating excellence: - Collect: learn from previous works stored in digital libraries, the web, etc. - Relate: consult with peers and mentors at early, middle and late stages - Create: explore, compose, discover, and evaluate possible solutions - Donate: disseminate the results and contribute to the digital libraries, the web, etc. Within this integrated framework, there are eight activities that require human-computer interaction research and advanced user interface design. This paper concentrates on techniques of information visualization that support creative work by enabling users to find relevant information resources, identify desired items in a set, or discover patterns in a collection. It describes information visualization methods and proposes five questions for the future: generality, integration, perceptual foundations, cognitive principles, and collaboration. Also cross-referenced as UMIACS-TR-9942 University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
The Design of History Mechanisms and their Use in Collaborative Educational Simulations. Catherine Plaisant. Anne Rose. Gary Rubloff. Richard Salter. Ben Shneiderman. May 1999.
Reviewing past events has been useful in many domains. Videotapes and flight data recorders provide nvaluable technological help to sports coaches or aviation engineers. Similarly, providing learners with a readable recording of their actions may help them monitor their behavior, reflect on their progress, and experiment with revisions of their experiences. It may also facilitate active collaboration among dispersed learning communities. Learning histories can help students and professionals make more effective use of digital library searching, word processing tasks, computer-assisted design tools, electronic performance support systems, and web navigation. This paper describes the design space and discusses the challenges of implementing learning histories. It presents guidelines for creating effective implementations, and the design tradeoffs between sparse and dense history records. The paper also presents a first implementation of learning histories for a simulation-based engineering learning environment called SimPLE (Simulated Processes in a Learning Environment) for the case of a semiconductor fabrication module, and reports on early user evaluation of learning histories implemented within SimPLE. Also cross-referenced as UMIACS-TR-99-34 University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Snap-Together Visualization: Coordinating Multiple Views to Explore. Chris North. Ben Shneiderman. June 1999.
Information visualizations with multiple coordinated views enable users to rapidly explore complex data and discover relationships. However, it is usually difficult for users to find or create the coordinated visualizations they need. Snap-Together Visualization allows users to coordinate multiple views that are customized to their needs. Users query their relational database and load results into desired visualizations. Then they specify coordinations between visualizations for selecting, navigating, or re-querying. Developers can make independent visualization tools 'snap-able' by including a few hooks. Also cross-referenced as UMIACS-TR-99-28 University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, Human-Computer Interaction Laboratory, University of Maryland,
Pixel Data Access for End-User Programming and Graphical Macros. Richard Potter. Ben Shneiderman. May 1999.
Pixel Data Access is an interprocess communication technique that enables users of graphical user interfaces to automate certain tasks. By accessing the contents of the display buffer, users can search for pixel representations of interface elements, and then initiate actions such as mouse clicks and keyboard entries. While this technique has limitations it offers users of current systems some unusually powerful features that are especially appealing in the area of end-user programming. Also cross-referenced as UMIACS-TR-99-27 University of Maryland Institute doe Advanced Computer Studies, Department of Computer Science, University of Maryland,
Visualizing Digital Library Search Results with Categorical and. Ben Shneiderman. David Feldman. Anne Rose. February 1999.
Digital library search results are usually shown as a textual list, with 10-20 items per page. Viewing several thousand search results at once on a two-dimensional display with continuous variables is a promising alternative. Since these displays can overwhelm some users, we created a simplified two-dimensional display that uses categorical and hierarchical axes, called hieraxes. Users appreciate the meaningful and limited number of terms on each hieraxis. At each grid point of the display we show a cluster of color-coded dots or a bar chart. Users see the entire result set and can then click on labels to move down a level in the hierarchy. Handling broad hierarchies and arranging for imposed hierarchies led to additional design innovations. We applied hieraxes to a digital video library used by middle school teachers and a legal information system. (Also cross-referenced as UMIACS-TR-99-12) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Understanding Patterns of User Visits to Web Sites: Interactive. Harry Hochheiser. Ben Shneiderman. February 1999.
HTTP server log files provide Web site operators with substantial detail regarding the visitors to their sites. Interest in interpreting this data has spawned an active market for software packages that summarize and analyze this data, providing histograms, pie graphs, and other charts summarizing usage patterns. While useful, these summaries obscure useful information and restrict users to passive interpretation of static displays. Interactive starfield visualizations can be used to provide users with greater abilities to interpret and explore web log data. By combining two-dimensional displays of thousands of individual access requests, color and size coding for additional attributes, and facilities for zooming and filtering, these visualizations provide capabilities for examining data that exceed those of traditional web log analysis tools. We introduce a series of interactive starfield visualizations, which can be used to explore server data across various dimensions. Possible uses of these visualizations are discussed, and difficulties of data collection, presentation, and interpretation are explored. (Also cross-referenced as UMIACS-99-11) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Creating Creativity for Everyone: User Interfaces for Supporting. Ben Shneiderman. February 1999.
A challenge for human-computer interaction researchers and user interface designers is to construct information technologies that support creativity. This ambitious goal can be attained by building on an adequate understanding of creative processes. This paper offers the four-phase genex framework for generating excellence: - Collect: learn from previous works stored in digital libraries - Relate: consult with peers and mentors at early, middle and late stages - Create: explore, compose, and evaluate possible solutions - Donate: disseminate the results and contribute to the digital libraries Within this integrated framework, this paper proposes eight activities that require human-computer interaction research and advanced user interface design. A scenario about an architect illustrates the process of creative work within a genex environment. (Also cross-referenced as UMIACS-TR-9910) University of Maryland, Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
LifeLines: Using Visualization to Enhance Navigation and Analysis of. Catherine Plaisant. Richard Mushlin. Aaron Snyder. Jia Li. Dan Heller. Ben Shneiderman. October 1998.
LifeLines provide a general visualization environment for personal histories. We explore its use for clinical patient records. A Java user interface is described, which presents a one-screen overview of a computerized patient record using timelines. Problems, diagnoses, test results or medications can be represented as dots or horizontal lines. Zooming provides more details; line color and thickness illustrate relationships or significance. The visual display acts as a giant menu, giving direct access to the data. (Also cross-referenced as UMIACS-TR-98-56) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Data Object and Label Placement For Information Abundant Visualizations. Jia Li. Catherine Plaisant. Ben Shneiderman. August 1998.
Placing numerous data objects and their corresponding labels in limited screen space is a challenging problem in information visualization systems. Extending map-oriented techniques, this paper describes static placement algorithms and develops metrics (such as compactness and labeling rate) as a basis for comparison among these algorithms. A control panel facilitates user customization by showing the metrics for alternative algorithms. Dynamic placement techniques that go beyond map-oriented techniques demonstrate additional possibilities. User actions can lead to selective display of data objects and their labels. Department of Computer Science, University of Maryland,
Emergent Patterns of Teaching/Learning in Electronic Classrooms. Ben Shneiderman. Ellen Yu Borkowski. Maryam Alavi. Kent Norman. July 1998.
Novel patterns of teaching/learning have emerged from faculty and students who use our three Teaching/Learning Theaters at the University of Maryland, College Park. These fully-equipped electronic classrooms have been used by 74 faculty in 264 semester-long courses since the Fall of 1991 with largely enthusiastic reception by both faculty and students. The designers of the Teaching/Learning Theaters sought to provide a technologically rich environment and a support staff so that faculty could concentrate on changing the traditional lecture from its unidirectional information flow to a more collaborative activity. As faculty evolved their personal styles in using the electronic classrooms, novel patterns of teaching/learning have emerged. In addition to enhanced lectures, we identified three common patterns: active individual learning, small-group collaborative learning, and entire-class collaborative learning. Department of Computer Science, University of Maryland,
Facilitating Network Data Exploration with Query Previews: A Study of. Egemen Tanin. Amnon Lotem. Ihab Haddadin. Ben Shneiderman. Catherine Plaisant. Laura Slaughter. February 1998.
Current network data exploration systems which use command languages (e.g. SQL) or form fill-in interfaces fail to give users an indication of the distribution of data items. This leads many users to waste time posing queries which have zero-hit or mega-hit result sets. Query previewing is a novel visual approach for browsing huge networked information warehouses. Query previews supply data distribution information about the database that is being searched and give continuous feedback about the size of the result set for the query as it is being formed. Our within-subjects empirical comparison studied 12 subjects using a form fill-in interface with and without query previews. We found statistically significant differences showing that query previews sped up performance 1.6 to 2.1 times and led to higher subjective satisfaction. (Also cross-referenced as UMIACS-98-14) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Codex, Memex, Genex: The pursuit of transformational technologies. Ben Shneiderman. December 1997.
Handwritten codexes or printed books transformed society by allowing users to preserve and transmit information. Today, leather-bound volumes and illuminated manuscripts are giving way to animated image maps and hot links. Vannevar Bush's memex has inspired the World Wide Web, which provides users with vast information resources and convenient communications. In looking to the future, we might again transform society by building genexes -- generators of excellence. Such inspirational environments would empower personal and collaborative creativity by enabling users to: - collect information from an existing domain of knowledge, - create innovations using advanced tools, - consult with peers or mentors in the field, and then - disseminate the results widely. This paper describes how a framework for an integrated set of software tools might support this four-phase model of creativity in science, medicine, the arts, and beyond. Current initiatives are positive and encouraging, but they do not work in an integrated fashion, often miss vital components, and are frequently poorly designed. A well-conceived and clearly-stated framework could guide design efforts, coordinate planning, and speed development. (Also cross-referenced as UMIACS-TR-97-89) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Previews and Overviews in Digital Libraries: Designing Surrogates to. Stephan Greene. Gary Marchionini. Catherine Plaisant. Ben Shneiderman. September 1997.
To aid designers of digital library interfaces and web sites in creating comprehensible, predictable and controllable environments for their users, we define and discuss the benefits of previews and overviews as visual information representations. Previews and overviews are graphic or textual representations of information abstracted from primary information objects. They serve as surrogates for those objects. When utilized properly, previews and overviews allow users to rapidly discriminate objects of interest from those not of interest, and to more fully understand the scope and nature of large collections of information resources. We provide a more complete definition of previews and overviews, and discuss system parameters and aspects of primary information objects relevant to designing effective preview and overviews. Finally, we present examples that illustrate the use of previews and overviews and offer suggestions for designers. (Also cross-referenced as UMIACS-TR-97-73) University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Design and Evaluation of Incremental Data Structures and Algorithms for. Egemen Tanin. Richard Beigel. Ben Shneiderman. May 1996.
Dynamic query interfaces (DQIs) are a recently developed database access mechanism that provides continuous real-time feedback to the user during query formulation. Previous work shows that DQIs are an elegant and powerful interface to small databases. Unfortunately, when applied to large databases, previous DQI algorithms slow to a crawl. We present a new incremental approach to DQI algorithms and display updates that works well with large databases, both in theory and in practice. (Also cross-referenced as UMIACS-TR-97-46 University of Maryland Insttitue for Advanced Computer Studies, Department of Computer Science, University of Maryland,
Interface and Data Architecture for Query Preview in Networked. Khoa Doan. Catherine Plaisant. Ben Shneiderman. Tom Bruns. October 1997.
There are numerous problems associated with formulating queries on networked information systems. These include data diversity, data complexity, network growth, varied user base, and slow network access. This paper proposes a new approach to a network query user interface which consists of two phases: query preview and query Rrefinement. This new approach is based on the concepts of dynamic queries and query previews, which guides users in rapidly and dynamically eliminating undesired datasets, reducing the data volume to manageable size, and refining queries locally before submission over a network. Examples of 2 applications are given: a Restaurant Finder and prototype with NASA's Earth Observing Systems--Data Information Systems (EOSDIS). Data architecture is discussed and user's feedback is presented. Dynamic queries and query previews provide solutions to many existing problems in querying networked information systems. Department of Computer Science, University of Maryland,
Elastic Windows: A Hierarchical Multi-Window World-Wide Web Browser. Eser Kandogan. Ben Shneiderman. May 1997.
The World-Wide Web (WWW) is becoming an invaluable source for the information needs of many users. However, current browsers are still primitive, in that they do not support many of the navigation needs of users, as indicated by user studies. They do not provide an overview and a sense of location in the information structure being browsed. Also they do not facilitate the organization and filtering of information nor aid users in accessing already visited pages without much cognitive demands. In this paper, a new browsing interface is proposed with multiple hierarchical windows and efficient multiple window operations. It provides a flexible organization where users can quickly organize, filter, and restructure the information on the screen as they reformulate their goals. Overviews can give the user a sense of location in the browsing history as well as provide fast access to a hierarchy of pages. Department of Computer Science, University of Maryland,
User Interfaces for a Complex Robotic Task: A Comparison of Tiled vs.. J.Corde Lane. Steven P. Kuester. Ben Shneiderman. January 1997.
High complexity tasks, such as remote teleoperation of robotic vehicles, often require multiple windows. For these complex tasks, the windows necessary for task completion, may occupy more area than available on a single visual display unit (VDU). Since the focus of the robotic task constantly changes, modular control panels that can be opened, closed, and moved on the screen are invaluable to the operator. This study describes a specific robotic task and the need for a multi-window interface that can be easily manipulated. This paper examines two multi-window management strategies: tiled (fixed size) and arbitrary overlap. Multi-window searches were performed using the two management styles and they were compared on the basis of search completion time and error rates. Results with 35 novice users showed faster completion times for the tiled management strategy than for the arbitrary overlap strategy. Other factors such as the number of windows available, the number of displayed windows, workload of opening or closing windows, and effect of learning are discussed. Department of Computer Science, University of Maryland,
Incremental Data Structures and Algorithms for Dynamic Query. Egemen Tanin. Richard Beigel. Ben Shneiderman. January 1997.
Dynamic query interfaces (DQIs) are a recently developed form of database access that provides continuous realtime feedback to the user during the query formulation process. Previous work shows that DQIs are an elegant and powerful interface to small databases. Unfortunately, when applied to large databases, previous DQI algorithms slow to a crawl. We present a new approach to DQI algorithms that works well with large databases. HCIL, Dept. of Computer Science, Univ. of Maryland,
Elastic Windows: Evaluation of Multi-Window Operations. Eser Kandogan. Ben Shneiderman. October 1996.
Most windowing systems follow the independent overlapping windows approach, which emerged as an answer to the needs of the 1980s' technology. Due to advances in computers and display technology, and increased information needs, modern users demand more functionality from window management systems. We proposed Elastic Windows with improved spatial layout and rapid multi-window operations as an alternative to current window management strategies for efficient personal role management [kandogan]. In this approach, multi-window operations are achieved by issuing operations on window groups hierarchically organized in a space-filling tiled layout. This paper describes the Elastic Windows interface briefly and then presents a study comparing user performance with Elastic Windows and traditional window management techniques for 2, 6, and 12 window situations. Elastic Windows users had statistically significantly faster performance for all 6 and 12 window situations, for task environment setup, task environment switching, and task execution. These results suggest promising possibilities for multiple window operations and hierarchical nesting, which can be applied to the next generation of tiled as well as overlapped window managers. Human-Computer Interaction Laboratory, Univ. of Maryland, Institute for Systems Research, Univ. of Maryland, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. July 1996.
The Eyes Have It: A Task by Data Type Taxonomy for Information Visualizations. 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 Human Computer Interaction Laboratory, Institute for Systems Research, Institute for Advanced Computer Studies, Dept. of Computer Science, Univ. of Maryland,
Rohit Mahajan. Ben Shneiderman. May 1996.
Visual & Textual Consistency Checking Tools for Graphical User Interfaces. 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) Human Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. April 29, 1996.
Designing Information-Abundant Websites. 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) Human Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Chris North. Ben Shneiderman. Catherine Plaisant. October 1995.
User controlled overviews of an image library: A case study of the Visible. 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) Human Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. Maryam Alavi. Kent L. Norman. Ellen Yu Borkowski. September 1995.
Windows of Opportunity in Electronic Classrooms. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research, College of Business, Department of Psychology, Computer Science Center,
Ben Shneiderman. Anne Rose. October 1995.
Social Impact Statements: Engaging Public Participation in Information. "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 Human-Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Khoa Doan. Catherine Plaisant. Ben Shneiderman. September 1995.
Query previews in networked information systems. 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 Human Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Catherine Plaisant. Brett Milash. Anne Rose. Seth Widoff. Ben Shneiderman. September 1995.
LifeLines: Visualizing personal histories. 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) Human Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Eser Kandogan. Ben Shneiderman. September 1995.
Elastic Windows: Improved spatial layout and rapid multiple window. 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) Human Computer Interaction Laboratory, Center for Automation Research, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Harsha Kumar. Catherine Plaisant. Ben Shneiderman. March 1995.
Browsing Hierarchical Data with Multi-Level Dynamic Queries and Pruning. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Catherine Plaisant. Ben Shneiderman. May 1995.
Organization overviews and role management: Inspiration for future desktop environments. 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) Human-Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Rohit Mahajan. Ben Shneiderman. April 1995.
A Family of User Interface Consistency Checking Tools. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Laura Slaughter. Kent L. Norman. Ben Shneiderman. March 1995.
Assessing users' subjective satisfaction with the Information System for. 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 Human Computer Interaction Laboratory, Department of Psychology, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ajit J. Vanniamparampil. Ben Shneiderman. Catherine Plaisant. Anne Rose. February 1995.
User Interface Reengineering: A Diagnostic Approach. 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) Human-Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, College of Business and Management,
Anne Rose. Ben Shneiderman. Catherine Plaisant. February 1995.
Using Ethnographic Methods in the Redesign of User Interfaces. 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) Human-Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Jason Ellis. Chi Tran. Jake Ryoo. Ben Shneiderman. June 1995.
Buttons vs. menus: An exploratory study of pull-down menu selection as. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. Richard Chimera. Ninad Jog. Ren Stimart. David White. May 1995.
Evaluating spatial and textual style of displays. 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 Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research, General Electric Information Service, Rockville, MD,
Toshiyuki Asahi. David Turo. Ben Shneiderman. June 1994.
Using Treemaps to visualize the Analytic Hierarchy Process. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Harsha Kumar. Catherine Plaisant. Marko Teittinen. Ben Shneiderman. June 1994.
Visual Information Management for Network Configuration. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Vinit Jain. and Ben Shneiderman. revised Sept. 1993.
Data structures for Dynamic Queries: An analytical and experimental evaluation. 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 Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Center for Automation Research,
Ninad Jog. Ben Shneiderman. May 1994.
Interactive Smooth Zoomming in a Starfield 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Ben Shneiderman. Catherine Plaisant. May 1994.
The Future of Graphic User Interfaces: Personal Role Managers. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Catherine Plaisant. David Carr. Ben Shneiderman. April 1994.
Image Browsers: Taxonomy, Guidelines, and Informal 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Vinit Jain. Ben Shneiderman. September 1993.
Data Structures for Dynamic Queries: An Analytical and Experimantal Evaluation.. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Christopher Ahlberg. Ben Shneiderman. September 1993.
The Alphaslider: A Compact and Rapid Selector. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Christopher Ahlberg. Ben Shneiderman. September 1993.
Visual Information Seeking: Tight Coupling of Dynamic Query Filters. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Masakazu Osada. Holmes Liao. Ben Shneiderman. April 1993.
AlphaSlider: Searching Textual Lists with Sliders. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. January 1994.
Dynamic Queries for 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Boon-Teck Kuah. Ben Shneiderman. November 1992.
Providing Advisory Notices for UNIX Command Users: Design,. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Andrew Sears. Ben Shneiderman. June 1993.
Split menus: Effectively using selection frequency to organize 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 Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Lewis R. Karl. Michael Pettey. Ben Shneiderman. July 1992.
Speech Versus Mouse Commands for Word Processing:. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Degi Young. Ben Shneiderman. May 1992.
A Graphical Filter/Flow Representation of Boolean. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Ehud Rivlin. Rodrigo Botafogo. Ben Shneiderman. March 1992.
Navigating in hyperspace: designing a structure based toolbox. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Holmes Liao. Masakazu Osada. Ben Shneiderman. February 1992.
Browsing Unix Directories With Dynamic Queries:. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Christopher Williamson. Ben Shneiderman. January 1992.
The Dynamic HomeFinder: Evaluating Dynamic Queries in a 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Christopher Ahlberg. Christopher Williamson. Ben Shneiderman. September 1991.
Dynamic Queries for Information Exploration:. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Ben Shneiderman. July 1991.
Visual User Interfaces for 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
William J. Weiland. Ben Shneiderman. July 1991.
A Graphical Query Interface Based on Aggregation/Generalization Hierarchies. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Andrew Sears. Doreen Revis. Janet Swatski. Rob Crittenden. Ben Shneiderman. April 1991.
Investigating Touchscreen Typing: the Effect of Keyboard Size on. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Brian Johnson. Ben Shneiderman. April 1991.
Tree-Maps: A Space Filling Approach to the Visualization of. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
R. Keil-Slawik. Catherine Plaisant. Ben Shneiderman. April 1991.
Remote direct manipulation:A case study of a. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Rodrigo A. Botafogo. Ben Shneiderman. April 1991.
Identifying Aggregates in Hypertext Structures. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Ben Shneiderman. March 1991.
Tree Visualization with Tree-maps: A 2-d space-filling approach. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Richard Chimera. Ben Shneiderman. September 1993.
An Exploratory Evaluation of Three Interfaces for. 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) Human Computer Interaction Laboratory, Institute for Systems Research, Dept. of Computer Science, Univ. of Maryland,
Rodrigo Botafogo. Ehud Rivlin. Ben Shneiderman. December 1990.
Structural analysis of hypertexts: identifying hierarchies and useful. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Tricia Jones. Ben Shneiderman. July 1990.
Examining usability for a training oriented hypertext: can hyper-activity. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Andrew Sears. Catherine Plaisant. Ben Shneiderman. June 1990.
A new era for high-precision touchscreens. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. Catherine Plaisant. Rodrigo Botafogo. Don Hopkins. William Weiland. May 1991.
Designing to facilitate browsing: A look back at the Hyperties. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Jacob (Kobi) Lifshitz. Ben Shneiderman. March 1990.
Window control strategies for hypertext traversal: an empirical study. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Catherine Plaisant. Ben Shneiderman. February 1991.
Scheduling home control devices: Design issues and usability. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Andrew Sears. Ben Shneiderman. June 1989.
High Precision Touchscreens:. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
William J. Weiland. Ben Shneiderman. August 1989.
Interactive graphics interfaces in hypertext systems. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Christos Faloutsos. Raymond Lee. Catherine Plaisant. Ben Shneiderman. June 1989.
Incorporating String Search in a Hypertext System:User. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Richard Furuta. Catherine Plaisant. Ben Shneiderman. May 1989.
A spectrum of automatic hypertext constructions. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
J. David Hobbs. Ben Shneiderman. May 1989.
Design, implementation, and evaluation of automatic spelling correction for. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Richard H.C. Seabrook. Ben Shneiderman. April 1989.
The user interface in a hypertext, multi-window program browser. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. September 1989.
Future directions for human-computer interaction. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Ben Shneiderman. December 1988.
Reflections on authoring, editing and managing hypertex. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
Richard Potter. Mitchell Berman. Ben Shneiderman. November 1988.
An experimental evaluation of three touchscreen strategies within a. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Jack Callahan. Don Hopkins. Mark Weiser. Ben Shneiderman. September 1987.
An empirical comparison of pie vs. linear menus. 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. Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Daniel Ostroff. Ben Shneiderman. Anita Komlodi. September 1987.
Selection devices for users of an electronic encyclopedia: an. 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) Human Computer Interaction Laboratory, Dept. of Computer Science, Univ. of Maryland,
John P. Chin. Kent L. Norman. Ben Shneiderman. July 1987.
Subjective user evaluation of CF Pascal programming tools. 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) Human Computer Interaction Laboratory, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. August 1987.
User interface design and evaluation for an electronic 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) Human Computer Interaction Laboratory, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. February 1987.
A taxonomy and rule-base for the selection of interaction styles. 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) Human Computer Interaction Laboratory, Dept. of Computer Science, Univ. of Maryland,
Sepeedeh Margono. Ben Shneiderman. June 1987.
A Study of File Manipulation by Novices Using Commands vs. Direct. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland, Institute for Systems Research,
James Baroff. Roland Simon. Francie Gilman. Ben Shneiderman. December 1986.
Direct manipulation user interfaces for expert 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Joseph F. Reisel. Ben Shneiderman. October 1986.
Is bigger better? The effects of display size on 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. Philip Shafer. Roland Simon. Linda J. Weldon. May 1986.
Display strategies for program browsing: concepts and an. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Ben Shneiderman. February 1986.
Empirical studies of programmers: the territory, paths, and. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Alan Laverson. Kent L. Norman. Ben Shneiderman. December 1985.
An evaluation of jump-ahead techniques for frequent menu users. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Larry Koved. Ben Shneiderman. April 1986.
Embedded menus: selecting items in context. 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) Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Kent L. Norman. Linda J. Weldon. Ben Shneiderman. August 1986.
Cognitive layouts of windows and multiple screens for user. 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) Human Computer Interaction Laboratory, Center for Automation Research, Department of Psychology, Univ. of Maryland, Dept. of Computer Science, Univ. of Maryland,
Jeffrey P. Schwartz. Kent L. Norman. Ben Shneiderman. March 1985.
Performance on content free menus as a function of study method. 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 Department of Psychology, Univ. of Maryland, Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Kent L. Norman. Jeffrey P. Schwartz. Ben Shneiderman. May 1984.
Memory for menus: effects of study mode. 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) Department of Psychology, Univ. of Maryland, Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
Diana Parton. Keith Huffman. Patty Pridgen. Kent L. Norman. Ben Shneiderman. June 1984.
Learning a menu selection tree: training methods compared. 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) Department of Psychology, Univ. of Maryland, Human Computer Interaction Laboratory, Center for Automation Research, Dept. of Computer Science, Univ. of Maryland,
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