Abstract
Digital libraries offer new opportunities to provide
access to diverse resources beyond those held in school buildings
and to allow teachers and learners to reach beyond classroom walls
to other people to build distributed learning communities. Creating
learning communities requires that teachers change their behaviors
and the Baltimore Learning Community Project
described here is based on the premise that access to resources should be tied to
the assessment outcomes that increasingly drive curricula and
classroom activity. Based on examination of curriculum guides
and discussions with project teachers, an interface for the BLC
digital library was prototyped. Three components (explore, construct,
and present) of this user interface that allows teachers to find
text, video, images, web sites, and instructional modules and
create their own modules are described. Although the technological
challenges of building learning communities are significant, the
greater challenges are mainly social and political.
Introduction
A variety of self-contained digital resources ranging
from drill and practice programs to shared MUDs and MOOs have
found their way into classrooms at all levels. Integrated, digital
libraries offer new opportunities to provide access to diverse,
primary resources beyond those held in school buildings and to
allow teachers and learners to reach beyond classroom walls to
other people to build distributed learning communities. This paper
describes the results of the first year of development of a learning
community known as the Baltimore Learning Community (BLC) that
links middle school teachers and learners through a shared multimedia
corpus of materials that support science and social studies. Part
of a five year project, we give an overview of key elements of
the BLC from a digital library perspective and focus on an interface
that provides cascading levels of user access.
Digital libraries have critical roles to play in
the evolution of learning and teaching that leverage the capabilities
of electronic information technologies. In addition to the usual
potentials of hypermedia and multimedia for teaching and learning
(e.g., broad, comprehensive access to materials; individualization;
and multiple media of representation), we have argued that digital
libraries will lead to increased integration in both spaces and
functions of learning, i.e., integration of workplace, home, and
school; and integration of work, informal learning, and formal
learning (Marchionini & Maurer, 1995). Furthermore, we believe
that bringing people and high-quality, well-organized digital
resources together though telecommunication channels will enable
new communities of practice devoted to learning and teaching (e.g.,
Pea, 1996). This belief was the basis for the BLC proposal to
the US Department of Education Technology Challenge Grant Program
(http://www.learn.umd.edu/papers
and proposal/proposal.html) which was funded
in September of 1995. The educational philosophies that underlie
this project are constructivist learning theory (e.g., Kafai &
Resnick, 1996) and outcome-oriented teaching practice (Nolet,
Marchionini, & Enomoto, in review).
The Baltimore Learning Community (BLC)
The Baltimore Learning Community is a collaborative
project of the University of Maryland at College Park (UMCP),
Johns Hopkins University (JHU), and the Baltimore City Public
Schools, funded as one of the US Department of Education Technology
Challenge Grants. The goal of this five-year project is to create
a learning community through use of high quality digital science
and social studies resources and high-speed networking. The project
has two major components that both target technology "have
not" schools that serve high numbers of students who are
academically at risk. One component of the project, lead by a
team of researchers from JHU, employs interactive video conferencing
and focuses on development of school-community links to facilitate
effective school to work transitions. The other component of the
project is lead by a team of researchers from the University of
Maryland at College Park and focuses on development of effective
solutions for integrating high quality digital video and other
resources into middle school science and social studies classrooms
and linking instruction that uses these resources to rigorous
curriculum guidelines measured by a statewide performance assessment.
This paper focuses on the UMCP component.
One goal of the Education Challenge Grants program
is to demonstrate how school- university-business consortia can
operate to improve educational outcomes through enhanced technology.
Thus, our focus is on implementing and testing an approach to
resources on demand that integrates techniques from varied research
and development projects and on gaining experience with logistical
and human-resource issues to inform other projects rather than
conducting basic research on learning principles or digital libraries.
In addition to the school and university partners, the BLC also
involves a consortium of public organizations and private businesses
that have made a major investment in the project. Discovery Communications
Inc. participated actively in the development of the original
project proposal and is providing up to 100 hours of digitized
video programming from the Discovery Channel and The Learning
Channel as well as ongoing technical and conceptual assistance.
Discovery aims to learn through this project how its large collection
of high-quality video resources may be repurposed in digital forms.
Apple Computer Inc. has donated 40 computers for the project.
The US National Archives and the Space Telescope Institute have
provided significant content resources in both digital and non-digital
formats.
Although the focus here is mainly on the technological
aspects of the project, a fundamental challenge in community building
is the logistics of human collaboration. The project brings together
15 teachers (six science, six social studies, three curriculum
coordinators), principals and other school system administrators,
more than a dozen UMCP faculty and graduate students, and industry
and government partners. Only one university staffer is full time
on the project, thus almost everyone associated with the project
has a full time jib beyond the project and teachers are especially
constrained by their teaching responsibilities through the daytime
hours. Thus, face-to-face meetings of the whole group are extremely
difficult to coordinate. Email and a BLC listserv play crucial
roles in facilitating communication and thus fostering community
building, but in the early stages of the project the faculty and
graduate student visits to schools serve as the glue of the community.
Monitoring the roles electronic media play in evolving the community
is an important aspect of the project evaluation.
At the time of writing, the BLC project had completed
one full year of work, during which time the first phase of implementation
was initiated. This phase includes acquiring and cataloging approximately
1500 digital objects; prototyping a WWW-based BLC gateway interface,
resource exploration component and module construction component;
conducting teacher training workshops and a summer institute;
installing 48 computers with basic Internet connectivity in 12
classrooms; creating a set of instructional modules based on the
first objects added; collecting baseline evaluation and research
data; and providing basic project server and communication services
to all participants.
Collection Development Policy and Procedures
The objects added to the BLC collection are determined
by several factors. First, since it is our intention to build
community, we have taken a user-centered perspective by involving
teachers in the selection process. Interviews with teachers and
regular written solicitations for specific materials are conducted.
Although content acquisition mainly aims at using Discovery, Archives,
and Space Telescope materials, we add WWW resources as well. Several
hundred images from the US Archives were acquired and digitized
during the summer of 1996 based on teacher requests. Discovery
Channel met with the BLC teachers in early Spring 1996 to determine
which topics would be of greatest interest to the community. As
a result, Discovery produced five hours of original science and
social studies programming based on existing footage for use in
the trial: "Aquatic Habitats," "The Space Shuttle,"
"Wonders of Weather," "How the West Was Lost,"
and "The Revolutionary War." These five programs aired
on Discovery Channel's educational service Assignment Discovery
in Fall 1996 and now make up the first installment of Discovery's
contribution to the digital library. Most recently, Discovery
and Learning Channel programming for 1997 was sent to teachers
and they were requested to identify those programs that should
be considered for digitization (note that Discovery itself must
go through a lengthy intellectual property rights process with
producers of its video before providing video programs or segments
to the project).
Secondly, the middle school social studies and science
curricula for the Baltimore City Public Schools was used to guide
acquisition. In addition to topics, curricula are shaped by school
district and state instructional outcome standards. The Maryland
State Performance Assessment Program defines outcome levels for
topics. Our interviews with teachers demonstrated that although
they select and organize instructional materials by topic (e.g.,
rivers), they must write and organize their lesson plans by MSPAP
outcome. Thus, we decided to use topic and outcome as two organizing
principles for collection development and access.
Five data types comprise the collection: text, images,
video, WWW sites, and instructional modules contributed by teachers.
Selection, acquisition, and management are described for each
data type. With the exception of Discovery materials, all objects
are in the public domain. In addition to teachers, UMCP faculty
and graduate students in science and social studies education,
and in information science are involved in content selection.
At present, a simple indexing scheme is used to create a record
for each object. This indexing is done by graduate students with
school library media emphases in conjunction with graduate students
with educational content emphases. For each object, 17 fields
are defined, including two main topics and subtopics and two outcome
categories each for both science and social studies. We have begun
investigating more sophisticated indexing schemes for the 1998-2001
phase of the project. We are currently considering the PARKA knowledge
representation system (Hendler, www.cs.umd.edu/projects/plus/Parka/parka.html).
Texts such as manuscript transcripts or public documents
are selected based on either specific teacher requests or assessments
made by project content specialists. If the document is not in
electronic form, it is scanned and OCRed and a bibliographic record
is created. At present, there are few texts included in the BLC
collection.
Many of the images were selected from the US Archives.
In addition to spending scores of hours at the Archives locating
and scanning images, images from a CD-ROM provided by the Archives
were selected. For each image, a thumbnail GIF file as well as
the full-size GIF is stored. For each image, a bibliographic record
is created.
Video tapes with time codes are provided by Discovery
and these tapes are segmented manually by project staff. Segments
are judged to be discrete conceptual units from an instructional
perspective and serve as individual video objects for indexing
and retrieval purposes. Because these are already highly structured
video programs made for instructional purposes (Learning Channel
programming), segmentation is straightforward with segments averaging
2 minutes. The segmentation data is then provided to the Discovery
team and MPEG 1 encoding is done. A CD-ROM for each program is
provided with separate MPEG files for each segment. These files
are then used as input to a program developed in the UMCP Center
for Automation Research (Kobla, Doermann, & Rosenfeld, 1996)
that identifies scene change frames. These frames, stored as GIF
files are considered to be to be candidate key frames for the
purposes of previews. A directory of potential key frames is thus
created for each video segment (between 30 and 80 candidate frames
are typical for a two-minute segment). Our present approach is
to manually select four key frames from these candidate frames
to best represent the segment for video previews that become part
of the bibliographic record for that segment. We are exploring
ways to automatically select key frames (e.g., the editing production
model may provide a principled approach to automatic selection,
Hampapur, Jain, & Weymouth, 1995). We are also experimenting
with alternative video preview mechanisms such as video wall,
fast forward, and parallel windows, and ways to take advantage
of textual transcripts for the video. A pilot study on fast forward
alternatives demonstrated linear degradation of accuracy on object
recognition tasks when fixed sets of key frames for video segments
were shown at 1, 4, 8, 12, and 16 frames per seconds. A slightly
less pronounced effect was found for gist recognition tasks at
these frame rates (Ding, in preparation). Likewise, we are exploring
ways to automate the segmentation and indexing processes by taking
advantage of transcripts for the Discovery Channel video (we also
have access to the less accurate closed-captioning for broadcast
programs). Additionally, summary and full transcripts for videos
will be available to users.
WWW sites are added to the collection upon recommendation
by teachers or project staff only if three conditions are met:
they must be clearly labeled as in the public domain; the site
must be maintained on an institutional server (e.g., government
agency, university, etc.) by an established group (no student
sites are included); and the site is fully traversed to follow
every link at least one level deep to determine whether possibly
objectionable content is referenced. Clearly, these last two conditions
are subjective. For sites meeting the conditions, a bibliographic
record is created. It should be noted that we aim to facilitate
the guidelines and policies that teachers using the Internet in
classrooms of the Baltimore City Public Schools follow.
Instructional modules are contributed by community
members voluntarily. Modules are created using a module construction
component of the BLC system (described below) and consist of materials
of any data types organized by instructional guidelines. In a
summer training institute during August 1996, teachers and project
staff created the first modules. Examples include: Baltimore's
environment, the Boston Tea Party, experiments in space, hurricanes,
rain forest, and women and war. At present, no peer review process
is used since the community is small and we must develop an experience
base for developing and managing such modules. In the third year
of the project, a community-based contribution procedure is planned
that cascades up from peers at the school level to the school
district level.
User Access
Access to BLC resources is customized for instructional
settings. Thus, access points are based on instructional topics
and instructional outcomes, and the interface is designed to support
the creation and use of instructional modules that include objects
from the BLC corpus. Interface representations and mechanisms
are guided by the view that information seeking is a dynamic,
and iterative decision-making process (Marchionini, 1995). This
view holds that except for known-item searches, information seekers
initiate search through a query or by focusing on a subset of
the dataset, examine objects rapidly to determine whether to examine
them more closely, either reject further examination and move
on in the dataset or conduct any number of more focused examinations
of the object at different levels of representation. This process
continues until the information need is satisfied or satisficed,
or the search is abandoned. Note that this view of information
seeking leverages organizational schemes that provide many levels
of representation for information objects-- ranging from terse
but informative surrogates such as titles to increasingly detailed
displays. In such schemes it is important to be able to quickly
reject objects for further examination and provide the user with
useful intermediate surrogates. In the BLC project these surrogates
are instantiated as object previews. We believe this perspective
is particularly crucial for bandwidth and storage intensive data
such as video and for users such as teachers who have little free
time for locating new instructional materials.
To support these access perspectives, we have chosen
to use a dynamic query interface approach (Ahlberg & Shneiderman,
1992; Shneiderman, 1994) that closely couples the query to results,
visualizes the data for highest level of surrogate (categories),
and supports rapid and incremental data exploration. The categorical
access points (topic and outcomes) present a special challenge
since display fields (e.g., starfield in Filmfinder, barfield
in Lifelines) are best applied to fine-grained, intervally-scaled
dimensions. Our initial solution to this challenge is to combine
a hierarchical structuring of data with a bar-graph by data type
for each topic/outcome combination. This component of the BLC
system is implemented in C++ (CodeWarrior) and will become a Netscape
plugin to the BLC gateway.
We considered a variety of attributes to use as filtering
variables in the interface. Topics, subtopics, subject (science
or social studies), outcome, format, and source (e.g., US Archives,
Discovery, WWW, etc.) are attributes that apply across all the
objects in the library. Note that all of these attributes are
categorical. Many other attributes apply to special types of objects.
Length is an interval attribute that may be of interest to users
but is format dependent. Although length of video in time units
would be most meaningful to users, temporal units do not apply
directly to the other formats. Byte length of files to be transferred
applies to video (ignoring streaming advantages), images, and
texts, but is more problematic with web sites and instructional
modules. For web sites, determining exactly which pages must be
transferred is difficult, plus sites are dynamic and may change
over time. Similarly, for instructional modules, should the byte
size of the module itself with only the pointers to data objects
or file sizes for objects as well? Certainly, teachers would benefit
from knowing how many data objects or better yet how many class
periods the module was designed to cover. Moreover, the modules
themselves are dynamic and every change would have to be reflected
in the underlying indexing information. Other attributes may be
very helpful to users but apply only to specific data objects,
for example, reading level based on one or more readability indexes
would be useful for texts but not applicable to other formats;
an approval rating or presence of teacher reflections would be
helpful for instructional modules but not applicable to other
formats. After some experience accrues, frequency of access (popularity)
values may be useful to consider.
Because one of the goals of the project is to influence teaching practice to be outcome oriented, we chose outcome as an attribute for one of the display axes. Based on conversations with teachers, it was clear that topic should be one of the classification attribute for the purposes of display. Thus, the first design decision was to use topics and outcomes as the axes. Because the topics and outcomes are specific to academic subjects, we require users to select science or social studies to determine what type of display is provided. Figure 1 shows a screen for the social studies category with main social studies topics on the vertical axis and social studies outcomes based on recommendations of the National Council for the Social Studies on the horizontal axis. Similarly, outcomes for science are based on recommendations by the National Science Teachers Association. For each main topic/outcome combination, a bar graph represents how many objects for each of the five data types have those attributes. Each bar graph has up to five bars with different colors representing different data types
(web site, image, video, text, module). For social
studies, there are twelve main topics and eight outcomes, yielding
96 bar graphs for the social studies objects. In Figure 1, there
are no web sites, several images, a few video clips, no texts,
and no instructional modules on the main topic "World History
by region" and outcome "Cultures." Note that the
database in this prototype system is sparsely populated with only
about 1500 objects Clicking on the video bar on this graph pops
up a list of video clip titles, and highlighting one of the titles
("Human Hunters") yields the display in Figure 2.
These object surrogates are similar to bibliographic
records, displaying basic attributes such as source and size (for
videos, time in seconds), a brief textual description, and a preview
(for videos, four manually selected key frames from the automatically
selected key frames). Selecting the record will initiate downloading
of the video clip (we are exploring other levels of surrogate
between the high-level preview and the full video clip). These
records may then be added to modules under construction or displayed
as stand-alone objects. Figure 3 illustrates a display for the
subtopics under "World History by Region." Note how
the bars in the main topic are now dispersed among the subtopics.
mThis first prototype has drawn good reactions from
teachers during various demonstrations but has not yet been implemented
for their use. There are several additional features to add and
some problems with the interface. We have begun to add a specialized
attribute for each of the two subject areas; time period for social
studies objects and science terms (organic/inorganic). Time will
be selected on a slider bar and science categories with radio
buttons. Existing objects will be reindexed to include these attributes.
Additionally, buttons for adding objects to the modules must be
added and some details added to the bibliographic records (e.g.,
units of size). At present, the bar lengths are treated as relative
lengths. Because we expect there to be wide-ranging distributions
in the density of objects for different topic/outcome combinations
and data types, and the number of pixels available for each bar
graph region is constrained (about 40 by 25 pixels for the Macintosh
monitors), the bar lengths are implemented as a proportion of
the highest number of objects on the screen. For example, the
highest bar on the social studies screen in Figure 1 has 80 objects,
so a bar representing 50 objects would be 50/80*25+1 or about
17 pixels high. To help users overcome possible confusion between
the visual and numeric values, a status display at the bottom
of the screen shows the number of items represented by a bar when
the cursor rolls over a bar. Whether this is sufficient requires
user testing feedback. Another potential problem for users is
the fact that many to many relationship indexing is done for objects
and attributes. Thus, a single object may appear as an element
in several different bars. Because a goal is to explore reuse
of data objects and indexing is inherently subjective, we believe
this is the best approach but will be certain to discuss this
in training and documentation.
Applying and Extending the Library: Module Construction
Finding information objects is only part of what
libraries are about. Although physical libraries provide a variety
of services to help users interpret and use information found
in their holdings, there is a strong privacy ethic that tends
to limit how much assistance librarians offer beyond access--that
is, what users do with the information accessed in libraries is
up to them, thus protecting their privacy while also minimizing
requirements on the human resources of the library. Just as special
libraries may offer post-access services (e.g., translation, patent
investigation, bibliography preparation), digital libraries that
are specialized can provide specialized tools and services to
assist users in interpreting, using, and communicating what they
access. For users of the BLC system, access is only the beginning--although
teachers or students could use the exploration component to do
on-the- fly searches during class, the main purpose is to help
teachers and students be more planful before class begins. Thus,
an important component of the system supports the creation of
instructional modules that tie topics, outcomes, procedures, and
evaluation together. The module construction component of BLC
allows teachers (and possibly students) to plan lessons that integrate
relevant objects from the library.
This component uses a WWW-based, form driven interface
which has five main sections: a general characterization section
with a few required fields, a before instruction section, a during
instruction section, an after instruction section, and a reflections
section. Figure 4 illustrates the main module construction form.
Title and teacher name are required but teachers are encouraged
to complete as much of the form as possible.
The outcomes button is linked to an electronic version
of the Maryland School Performance Assessment Program (MSPAP)
outcomes for social studies and science so that teachers can easily
link their modules to these outcomes that are assessed each year
in every public school in Maryland. These outcomes and accompanying
indicators are more extensive and localized than the outcomes
used on the horizontal axis of the exploration module which are
based on recommendations of national professional organizations.
By separating the state standards in this manner, users in other
states could easily substitute their specific outcomes and indicators
without having to change the exploration or module construction
components.
The before instruction section allows teachers to
specify the type of learning activity planned, groupings, and
type of cognitive operations, as well as make notes about activities
and required resources (in particular objects from the database).
Figure 5 illustrates this section. The during instruction section
allows teachers to specify what students are going to do as well
as what the teacher will do. The after instruction section allows
teachers to specify evaluation and follow up activities, and the
reflections section is meant to allow teachers to comment on the
effectiveness of the module and make notes that other teachers
might find useful or they themselves might want to consider when
using the module another time. Because we want to grow a community,
it is important that teachers use the reflections before contributing
the module to the BLC corpus.
In addition to the module construction component,
a presentation component will allow teachers or students to present
a module without all of the instructional details contained in
the module. Figure 6 illustrates the first prototype of the presentation
component. Based on teacher feedback, this component is being
revised to work more like a simple slide show presentation that
will be driven by simple forward, back, start, and end buttons
so that teachers or students can easily use it during class sessions.
System Development & Project Evaluation
The main emphasis here is on the interfaces for object
access and usage, however, there are several architectural issues
the BLC project must address. First, the objects must be delivered
from the BLC server to individual classrooms. The original plan
was to lease T1 lines for each of the schools and then use the
Ethernet local area network within each of the buildings to deliver
content to individual workstations. In the past two years since
the proposal was developed, the telecommunications picture has
evolved considerably. For the first year of the project, low speed
(56kps) frame relay service was provided for each school to establish
Internet connectivity and familiarize teachers with networking
capabilities. In the first phase of the project, while many of
the components of the system are being developed, large hard disks
(4 gB) on a teacher workstation in each classroom will serve to
store specific modules in use for a few weeks and large files
will be downloaded from the Sun SparcStation server over night.
This solution seems particularly appropriate given Andreessen's
recent comment on replication: "Bandwidth and telecommunications
infrastructure cost more than disk storage (home.mcom.com/comprod/columns/
techvision/replication.html)." Our plan
is to use Starlight video server software to stream video objects
from the server to the Macintosh clients once a high-speed solution
is determined. For the next phase of the project, we are investigating
three alternatives: fiber connections leased from the local phone
company, cable modems connected to the cable feed from the cable
company that serves the city of Baltimore, and a hybrid wireless
solution. In the first case, lines would be leased from Bell Atlantic.
We are exploring the possibilities with TCI to provide the cable
solution and investigating ways to use Direct PC or other wireless
solutions for downlinks. The IBM Interactive Data Carousel solution
used in the EduPort project seems particularly interesting as
a wireless approach (Chernock, R., 1996; Ruiz, Masullo, &
El-Shishiny, in press). The decision on high speed connectivity
will be made late in 1997 as the database expands and the first
prototype system components have been user tested and ready for
revision.
The BLC gateway (see Figure 7) includes other components
for email, community listservs, video conferencing (planned for
the next phase), and links to other electronic resources. Because
the success of the project is so dependent on teacher participation,
we have provided each teacher with Internet access through a local
service provider and a 28.8 modem for use with their home computers.
All but a few of the 15 teachers had home computers and those
that did not borrowed one of the classroom computers over the
summer. In addition to the 2 day summer institute held in the
summer of 1996 where teachers used the database at the University
of Maryland to create their first instructional modules, inservice
meetings at the schools have been held on a variety of topics
and graduate students and faculty from the project visit the schools
on a regular basis to provide support and document progress. The
Discovery Channel has conducted workshops on the use of video
in the classroom and video tapes of a variety of their programs
have been made available to participating teachers. The intention
is to provide a pedagogical basis for using video and other resources
beyond the textbooks and materials in the classroom and to develop
a community perspective that extends the resources for students
and teachers beyond the classroom walls. In addition, we can learn
how instructional strategies change when teachers have control
over fine-grained video objects (about 2 minute clips) rather
than entire programs. A variety of evaluation efforts are underway.
Baseline interviews have been conducted with project staff and
participants (Enomoto, in preparation), teacher questionnaires
were used at the summer institute, the project electronic lists
are logged, and observations are made in the different classrooms
on a regular basis. We are particularly interested in discovering
how teaching behavior evolves as a result of the project and what
factors influence community building.
Conclusion
There are few unique research elements of the BLC
project. What is unique is how the fruits of research and development
are integrated over a fairly long period of time in working school
environments. Thus, some of the biggest challenges (as in physical
libraries) are social and political rather than technological.
Coordinating the efforts and needs of more than a dozen teachers,
several administrators, more than a dozen project staff, and hundreds
of students requires community building techniques and practice.
We fully expect that the work of the first two years will be revised
for the later phases of the project--new indexing schemes, updated
interfaces, much more data, a more integrated networking solution,
and more customized inservice training and evaluation experiences
will emerge based on the experience and testing of the first-phase
prototypes described here. Perhaps the most difficult challenges
and most valuable contributions will be in determining how much
human commitment is required to insure that content plus connectivitiy
does lead to community.
References
Ahlberg, C. Williamson, C. & Shneiderman, B.
(1992). Dynamic queries for information exploration: An implementation
and evaluation. The Proceedings of ACM CHI, 1992 Monterey
CA, (May 3-7) pp 619-626.
Chernock, R. (1996). Disc in the sky. EduPort
Newsletter, 1(6). Available from Eduport@umlvm.unl.edu.
Ding, W. (in preparation). An experiment on video
browsing.
Enomoto, E. (in preparation). BLC Formative evaluation
report. (http://www.learn.umd.edu/reports)
Hampapur, A., Jain, R., & Weymouth, T. (1995).
Production model based digital video segmentation. Multimedia
Tools and Applications, 1(1), 9-46.
Kafai, Y. & Resnick, M. (1996). Constructivism
in practice: designing, thinking, and learning in a digital world.
Mahwah, N.J.: Lawrence Erlbaum.
Kobla, V., Doermann, D., & Rosenfeld, A. (1996).
Compressed domain video segmentation. Technical Report CAR-TR-839
CS-TR-3688, University of Maryland.
Marchionini, G. (1995). Information seeking in
electronic environments. NY: Cambridge University Press.
Marchionini, G. & Maurer, H. (1995). The roles
of digital libraries in teaching and learning. Communications
of the ACM, 38(4), 67-75.
Nolet, V., Marchionini, G., & Enomoto, E. (in
press). Combining Dynamic Query and Full Motion Digital Video
in a High Speed Network to Improve Instruction in Middle School
Science and Social Studies Classes. Proceedings of ED-MEDIA
97 (Calgary, British Columbia).
Pea, R. (1996). Computer support for knowledge building
communities. In T. Koschmann (Ed.) Computer support for collaborative
learning: Theory and practice of an emerging paradigm. Mahwah,
N.J.: Lawrence Erlbaum.
Ruiz, A., Masullo, M., & El-Shishiny, H. (in
press). A regional broadcast-centric educational services solution.
Submitted to IEEE Symposium on Computers and Communications:
ISCC '97.
Shneiderman, B. (1994). Dynamic queries for visual
information seeking. IEEE Software, 70-77.
Williamson, C. & Shneiderman, B. (1992). The
Dynamic HomeFinder: Evaluating dynamic queries in a real-estate
information exploration system. In Proceedings of ACM SIGIR,
339-346.