CDRL __________
CONTRACT N66001-95-C-8621
Date of Report
12 January 1998
SUBMITTED TO
Receiving Officer
e-mail address: "caetinrad@nosc.mil"
Rich Laverty Frank Schindler Bob Medearis 619-553-2918 619-553-2845 619-553-6377 laverty@nosc.mil fschindl@nosc.mil medearis@nosc.mil
SUBMITTED BY
Daniel D. Suthers
Learning Research and Development Center
University of Pittsburgh
Pittsburgh, PA 15260
Phone: 412-624-7036
Fax: 412-624-9149
email: suthers+@pitt.edu
Do not distribute to DTIC or other data depositories.
Distribution authorized to DOD components only; premature dissemination
(date). Other requests shall be referred to Naval Command, Control and Ocean
Surveillance Center (NCCOSC), RDT&E Division, San Diego, California
92152-5000.
1.
Preliminary Information
1.1
Report Title
Collaboration, Apprenticeship, and Critical Discussion: Groupware for
Learning
FIGURE 1. BELVEDERE INQUIRY DIAGRAM AND ADVICE
FIGURE 2. THE BELVEDERE INTERFACE
FIGURE 3: ABSTRACT IMPLEMENTATION LAYER
FIGURE 4. EXAMPLE ADVICE CONSISTENCY PATH.
FIGURE 5. "SNIPPETS" MAY BE REFERENCED BY CLICKING ON DOCUMENT ICONS.
FIGURE 6. WEB-BASED MATERIALS FOR CHALLENGE PROBLEM
FIGURE 7. SAMPLE ASSESSMENT RUBRICS
FIGURE 8. ARCHITECTURE REFERENCE MODEL.
FIGURE 9. SCIENCE LEARNING SPACE DEMONSTRATION.
FIGURE 10. LEARNING SPACE DEMONSTRATION ARCHITECTURE.
1.5
List of Symbols, Abbreviations, and Acronyms
Project PIs are indebted to Kirstie Bellman for her visionary leadership,
to Neil Jacobstein for his facilitation as cluster
leader, to Gary Bridgewater for the many ways in which he coordinated our work, to Bill Bewley, Sue Latzko, and their colleagues at ISX for
coordination of site visits, to Lila Cheville for helping us coordinate with
the DoDEA curriculum, to Lynne Gilfilian for evaluation, and to Frank Belz for
useful discussions about architecture. The Belvedere client was programmed by
Kim Harrigal and Dan Jones; the collaborative database server by Dan Jones; and
automated coaching by Dan Suthers and Joe Toth. Science materials were prepared
by Eva Toth and Arlene Weiner. On-line help and user interface testing was
performed by John Connelly. Sandy Katz contributed to evaluation planning. Dan
Suthers was technical lead and project manager.
2.
Body of the Report
2.1
Summary
Under CAETI funding, the Advanced Cognitive Tools for Learning project
designed, implemented and delivered one of the most ambitious and comprehensive
packages of the CAETI program [Suthers & Jones, 1997; Toth, Suthers &
Weiner, 1997]. This package begins with a sophisticated client-server
software system for supporting collaborative critical inquiry. This
software, known as "Belvedere," focuses and prompts students' cognitive
activity by giving them a graphical language to express the steps of
hypothesizing, data-gathering, and weighing of information. It provides
apprenticeship in science by suggesting next possible steps, and by cognitively
motivated structuring of materials and activities. It supports collaborative
learning through the shareability of diagrams by students in same-time
same-place, same-time distant or asynchronous modes, as well as through
text-based "chat" windows. Belvedere is based on a client-server architecture
that can deliver advanced educational technology on a variety of platforms,
requiring only that user machines run Java and have a few standard tools such
as a Web-browser, a word processor and a spreadsheet.
However we went much further than handing raw technology to the schools - we
also provided comprehensive support for implementation and integration in
the classroom and curriculum. Situated in a well-known institute for the
study of school learning, we are sensitive to the many demands and
opportunities that school reform places on teachers and schools. Already
experienced with classrooms, we listened carefully to DoDEA curriculum
supervisors and teachers, developed curriculum materials keyed to the DoDDS
curriculum standards and objectives, and modified materials and software in the
development process . Our "science challenge" activities are designed
to match and enrich the DoDDS curriculum, and are based on standards such as
the National Research Council's NSES, LRDC's New Standards, and the AAAS
Benchmarks for Science Literacy. We also provided students and teachers with
assessment rubrics which serve to scaffold student activities and guide peer
review, as well as help the teacher assess nontraditional learning objectives.
2.2
Introduction
Our fundamental belief is that learning is produced by extended
engagement of students in complex cognitive activities, involving
peers, experts, teachers, or intelligent systems as partners, which offer means
for (1) generating new ideas, (2) reflecting on ideas and
recent cognitive activity, (3) accessing useful information, (4)
motivating participation , (5) scaffolding for
performances somewhat beyond their competence, and (6) facilitation of
a long-term agenda for learning. We are at a watershed at which a number of
approaches that previously were beyond real world use are now feasible, but
each approach seems to lack some of the six basic affordances just listed.
Below we consider four major forms of learning systems, to motivate our own
technical approach.
An important form is the intelligent tutoring system (ITS). Quite a number have been built, at least in prototype form. Most have emphasized student modeling and providing feedback in the form of statements about knowledge deemed to be missing from the student. Several labs, notably John Anderson's, have pursued a scheme called model tracing, in which an intelligent critic intervenes whenever the student deviates from an "expert" approach in solving a set problem [Anderson & Pelletier, 1991; Anderson, et al. 1995] A different approach is associated with the work in Roger Schank's lab, in which cases are indexed according to situational properties of impasses or breakdowns that occurred within them. When a case becomes relevant because it matches a current realized or potential breakdown, the system offers to tell the student a "story" that might be helpful. Finally, our coached apprenticeship scheme provides all six affordances, but, at the outset of this project, only for technical jobs and only in purely computer-human interactions, rather than collaborative interactions of students with each other and with teachers. Consequently, we set out to adapt our approach to school curriculum. Consistent with research that shows that students learn better when they actively pursue understanding rather than passively receiving knowledge [Chi et al 1989, Resnick & Chi 1988, Webb 1989] the classroom teacher is now being urged to become a "guide on the side" rather than "the sage on the stage." New roles have also been recommended for tutoring systems that parallel the teacher's new role in "decentered" classrooms [Chan & Baskin, 1988; Clancey, 1992; Roschelle, 1994]. Hence work was addressed towards tutoring systems that augment the learning processes of students engaged in collaborative critical inquiry [O'Neill & Gomez, 1994; Slavin 1990].
A second form is the exploratory environment , such as a simulation of friction-free movement of objects. Exploratory environments provide many opportunities that might stimulate learning-producing activity among student peers and with teachers, but such systems characteristically lack any kind of advisor to explain, coach, and scaffold learning. They also tend to lack any structure for facilitating an explicit learning agenda. Still, we borrow from the exploratory microworlds form the notion of having kits that students can use to configure environments from which they might learn something.
A third form is systems to support authoring and, more generally, communications . Students routinely use word processing in schools now, for example, and modest beginnings of groupware for learning can be found. In the most innovative experiments, students author multimedia "publications," an approach we will be promoting as well. A variety of low-bandwidth interaction forums, MUDs, for example, are also being used in experimental learning research efforts and by some innovative teachers. However, the tools for developing substantial interactions and for publishing substantial bodies of work are just beginning to be developed to support learning activities. We planned to focus on a piece of this problem, tools to support (scaffold) the expansion from simple, narrative communications to communications of arguments, especially comparisons of alternative theories and debates over alternative public policies. In such dialectical activities, communications are more complex, there is more need for diagrammatic tools and other intelligent support for students, and there is great need to quickly recast subsets of discussion in different forms. For this reason, we saw the development of authoring, advising, and interacting capabilities for diagrammatic representations of arguments to be of central importance to stimulating a new level of high-order thinking and interaction over networks.
A fourth form is technology to support collaborative learning. There are at least three motivations driving the growing interest in this approach. The first is a practical one: having more than one student use instructional software is a cost saver. Also, there are seldom enough computer workstations for every student. The second (and perhaps primary) motivation is a response to the abundant research showing that collaborative learning correlates with a wide range of positive outcomes. Within non-computer-based, classroom and laboratory settings, collaborative learning has been shown to correlate with greater learning, increased productivity, more time on task, transfer of knowledge to related tasks, higher motivation, and heightened sense of competence [Johnson & Johnson, 1989; Rysavy & Sales, 1991; Sharan, 1980; Slavin, 1990]. Similarly, Webb's [1987] review of the research on collaborative use of instructional software suggests that it is at least as effective as individual use, and is sometimes superior [e.g., Johnson et al., 1985; Justen et al. 1990]. However, there is also widely recognized room for improvement. Collaborative learning does not work for all learners, and the results of instructional outcome studies are mixed [Klein & Pridemore, in press, Webb, 1987]. Fruitful student interactions are simply not a given. We can not expect learning gains to happen just because students are sitting together, at a desk or at a computer workstation. In Brown and Palincsar's [1989] words: "Social interactions do not always create new learning; peer interactions vary enormously; only some teaching environments actually create ideal learning experiences." (p. 397) Thus, the third motivation to develop CSCL systems is to improve the effectiveness of collaborative learning as an instructional format: i.e., to support peer interactions so as to increase learning gains.
These cognitive and social barriers to fruitful collaborative interactions raise an important challenge for teachers and developers of CSCL environments: to identify the features of collaborative learning situations that potentiate learning and to build learning environments which contain these features. At the outset of this work, we had been addressing this objective in two projects by designing and implementing tools which support question-asking, explanation, and critical discussion - i.e., the "knowledge articulation" activities which underlie social learning - particularly, for collaboration across networked machines. In the Belvedere project, our goal is to support students learning to engage in critical discussion of competing scientific theories. This work has resulted in a graphical argumentation environment in which students articulate and compare alternate theories and their associated arguments, and change them in response to new evidence or criticism [Suthers et al. , 1995; Suthers & Weiner, 1995]. The Sherlock troubleshooting environment for a complex electronics device contains tools to support peer critique of student solution traces. [Lesgold et al., 1992; Katz et al., 1993; Katz & Lesgold, 1994]. Students can step through a peer's solution, and select from a menu of "troubleshooting standards" those standards that the student did not follow, at a particular step of his solution. The software also has the capability to attach a menu of questions to domain objects, such as components in circuit diagrams.
Several system developers have been building instructional software which is specially tailored for collaborative use - i.e., CSCL systems [McManus & Aiken 1993; Newman 1991; Scardamalia et al. 1992; Whitelock et al. 1991]. However, none of these systems, to our knowledge, were being built upon a foundation of empirical research on collaborative cognition in the target domain of instruction. We believe that it is critical to ground the development of CSCL systems in research which addresses issues such as the following: What types of knowledge do students seek from their peers while collaborating on problem-solving activities? Are there any patterns in the types of knowledge that students can/can not readily explain to their peers? To what extent do students ask the right questions at the right time; i.e., do they know what they need to know in order to overcome an impasse during problem solving? What is the nature of human tutors' support for students, during collaborative problem solving and individual or collaborative critique of peer solutions? For example, what is the content and structure of human tutors' explanations for particular types of questions? Is human coaching primarily directive or question-driven? To address these questions, we had been working with small groups of students engaged in analysis of scientific debates in the Belvedere environment. We had also begun to carry out observational studies of students working together on Sherlock problems, and critiquing traces of peer solutions, with system coaching suppressed but a human tutor available to ask questions to when they are stuck (i.e., unable to help each other). This work prepared us to inform the development of a computer model of support for peer collaboration during particular types of activities (e.g., peer critiquing, collaborative problem solving).
A major motivation was the concern that knowledge-based educational software, such as intelligent tutoring systems, have historically been large, self-contained programs with specialized platform requirements. We saw that to make these technologies viable, we must be able add component functionality incrementally, and enable systems to interoperate with commercial software and internet resources [Brusilovsky, et al. 1996; Ritter & Koedinger, 1995; Roschelle & Kaput, 1995]. We knew that to reduce the cost of materials prepared by developers, and to enable greater collaboration between users, representations of educational materials should be shareable between diverse applications across the internet. Interoperability and reuse considerations suggested a "lowest common denominator" approach, yet we did not want to limit support for more advanced functionality such as domain-specific coaching. We also saw a great need to leverage productive software engineering technology, standard off-the-shelf commodities, and standard information packaging protocols in order to make educational technology more affordable. We had refined our software engineering capabilities toward this end, and planned to leverage SGML and especially its World-Wide Web expression in our work.
Thus, we started in a good position to develop and evaluate intelligent
network-based technology for supporting critical discussion, problem solving,
and use of on-line information resources, within both declarative work
environments, such as texts and arguments, and procedural resources, such as
simulations and problem-solving task environments.
2.3
Methods, Assumptions, and Procedures
In the following sections we begin by giving an overview of the software we
developed, from the point of view of the interface, overall behavior, and
design motivations for these. Then we describe the underlying architecture,
focus more specifically on coaching functionality, and conclude with a
discussion of the substantial supporting materials that we developed in
addition to the software.
2.3.1
Overview of Belvedere
The "Belvedere" software is a complete redesign and reimplementation of a
system of the same name, previously reported in [Suthers, et al. 1995;
Suthers & Weiner, 1995]. Belvedere's core functionality is a shared
workspace for constructing "inquiry diagrams," which relate data and hypotheses
by evidential relations (consistency and inconsistency). The implemented system
also includes groupware and associated tools that support students engaged in
critical inquiry processes, such as investigating a scientific problem:
The diagramming window is shown in Figure 1, with a student-generated
"inquiry diagram" and a window (in the lower right corner) displaying advice
from a coach. The default "palette" (the horizontal row of icons near the top
of Figure 1) makes salient the most crucial distinctions we want students to
acquire in order to conduct scientific inquiry. Left to right, the icons are
"data" for empirical statements, "hypothesis" for theoretical statements,
"unspecified" shape statements about which students disagree or are uncertain;
then links representing "against" and "for" evidential relations, and a link
for conjunction. Students use the palette by clicking on an icon, typing some
text (in the case of statements) and optionally setting other attributes, and
then clicking in the diagram to place the statement or create the link. The
remaining icons at the right end of the palette provide sources of counsel and
knowledge: they are a light bulb representing "ideas" from the coach, an
"in-box" that can receive information from Web pages, and (optional and not
shown in the figure) icons that start other applications such as a Web browser.
A "Guide" menu (upper right of Figure 1) provides students with suggestions on
how to use the software through five "phases of inquiry" (explore, hypothesize,
investigate, evaluate, and report).
We use a diagrammatic interface for cognitive, collaborative, and evaluative
reasons. First, the cognitive: concrete representations of abstractions turn
conceptual tasks into perceptual tasks. Thus the diagrams help students "see"
and internalize these abstractions and keep track of them while working on
complex issues. Second, the collaborative: diagrams support
collaboration by providing a shared context and reference point. Third, the
evaluative: student-constructed diagrams provide the teacher and the computer
with a basis for assessing students' understanding of inquiry in general and of
a topic area in particular. These three reasons are discussed further below.
2.3.1.1
Cognitive Support
2.3.1.2
Collaborative Support
Diagrams support collaboration by providing a shared context and reference
point. These advantages manifest in different ways depending on whether
the students are co-present or collaborating over the network. When they are
co-present, diagrams support collaboration by helping students keep track of
and refer to ideas under discussion, whether using a single display, or two
displays near each other. In these situations students often use gestures on
the display to indicate prior statements and relationships. In some group
configurations we have seen students work independently, then use gesturing on
the display to re-coordinate their collaboration when one student finds
relevant information. This can occur when information is brought to the group
from off-line sources, such as hands-on experiments. Distally, students can
work in parallel on the same workspace, as long as they are not editing the
same object at the same time. On networked computers, all changes are
propagated to others working with the same diagram in a "what you see is what I
see" manner. In addition to the diagram, a "chat" facility and a remote
pointing mechanism support unstructured natural-language conversations, needed
to coordinate the more structured inquiry diagramming when collaborating at a
distance.
2.3.1.3
Evaluative Support
Student-constructed diagrams provide the teacher and the computer with a basis
for assessing students' understanding of scientific inquiry, as well as of
subject matter knowledge. This assessment can support computer coaching of the
inquiry process. As described in section 2.3.3, we have constructed two types
of coaches. One provides general advice on the structure of the inquiry diagram
from the standpoint of scientific argumentation. It helps the students
understand principles of inquiry such as: hypotheses are meant to explain data,
and are not accepted merely by being stated; multiple lines of evidence
converging on a hypothesis is better than one consistent datum; one should seek
disconfirming evidence as well as confirming evidence (addressing the
confirmation bias, as shown in Figure 1); discriminating evidence is needed
when two hypotheses have identical support; circular arguments are problematic;
etc. The other coach performs various comparisons between the students'
diagrams and an inquiry diagram provided by a subject matter expert. This coach
can provide students with feedback concerning correctness, or confront students
with new information (found in the expert's diagram) that challenges students
in some way.
2.3.1.4
Other Features
Other features of Belvedere, briefly noted, include the following. Students can
set different "belief levels" for the statements and relations, and display
these as line thickness with a "filter." References to external objects can be
sent from other applications to an "in-box" (right hand icon of Figure 1) for
optional placement in the diagram at the students' convenience. We and our
students regularly use this in-box mechanism to send references to Web pages
containing relevant information. Once placed in an inquiry diagram, Belvedere
provides a hyperlink back to the referenced Web page. Thus Belvedere can be
used as a structured "hotlist" to organize Internet resources.
2.3.2
Architecture
This section describes the architecture underlying the Belvedere system. Our
notion of "architecture" is multifaceted, encompassing all aspects of the
design of the software. In this section, we use four levels of description for
software systems proposed by CAETI colleagues Frank Belz and David Luckham
[Luckham et al., 1997]: Interface Presentation, Concepts of
Operations, Abstract Implementation, and Resource. In analyzing our own work we
have found it useful to begin with a fifth level of description, Concepts of
Application, that is independent of the software. This is necessary for design
and evaluation with respect to intended objectives. Further discussions with
Tom Wheeler of Army CECOM further clarified our concepts of these abstraction
layers. Along with Belz, Luckham, and Wheeler, we claim that clarity about
level of description helps avoid misunderstandings due to talking at different
levels, and enables one to choose to use an existing architecture at one level
while rejecting or changing it at another level. (See section 2.3.5.1 for
further discussion of this abstraction hierarchy and the collaborations that
led to it.)
Each of the following sections begins with a general characterization of the
corresponding level of description, followed by an informal description of our
application or architecture at that level, and a summary of mappings to other
levels of description. At each level we discuss reusability and
interoperability concerns, and the advantages and disadvantages of our design.
2.3.2.1
Concepts of Application
At the level of concepts of application, one begins by describing the
application domain largely in its own terms (as practitioners view it), and the
educational objectives or other task objectives. Then, through cognitive task
analysis or other methodology, one identifies barriers to these objectives, and
chooses those which the software might be expected to help overcome.
Belvedere is designed to be used in conjunction with materials presented in a Web browser. The materials are segmented into units at a granularity which a subject matter expert chooses for his or her own inquiry diagrams. "Reference This" buttons in the Web pages enable students to send "references" to these segments into the Belvedere "in-box" (upper right of Figure 2) from where they may be dragged into the inquiry diagram as needed. The small icons in the upper left of each shape indicate that hyperlinks can be followed back to the original document.
Summarizing from Suthers et al. [1995] and Suthers & Weiner [1995], here is how the interface is designed to address barriers to learning critical inquiry:
Inquiry Diagrams. Inquiry diagrams consist of a problem statement, and a collection of statements and relationships between them. The operations abstract communications between the Belvedere interface and a persistent object store. Some of these are New Inquiry Diagram (A2), Open Inquiry Diagram (A2), Add Statement (A3, A4), Add Relationship (A3, A4), Update Statement (A5, A7), and Delete Statement or Relationship (A5) (we retain a complete history of all objects that existed).
Information Search. Accomplished by Get Page (A1) and Send Reference (A3, A4), invoked via the Web browser.
Discussion with Others. A8 is accomplished by Send Message.
Advice Services. Objects include requests, replies, and interruptions; all in support of A9. The client can Request Advice; and the coach can Send Advice, which consists of the advice text and a list of the objects that the advice text refers to. The coach can also send an Interruption, which is a request to perform an interface action that notifies the user that advice is available.
Some important Concepts of Application activities are not supported by this model. These include performing data analysis and visualizations (A4, A5), asking the coach specific questions (A9), and abstracting summaries of the inquiry (A6). Extensions are being planned to address these concerns.
The above design is limited in several ways. Some of the protocols are application specific. This is probably unavoidable; although some reuse may be facilitated by shared ontologies at the Concepts of Operations level. Under new PTI funding, we have begin another cycle of redesign to enable delivery using other databases and other server class machines. Prototype versions of RMI and CORBA server interfaces have been implemented and are currently undergoing testing and evaluation. Our new design will also greatly simplify the addition of new types of clients. (We plan to add clients that manipulate influence diagrams, causal loop diagrams, and concept maps.) Under the new design the protocols are data-driven, so that only minor modifications to the Session Manager (and no other existing components) are required to add a new type of client. Each client would load a data type table into the Database.
We are attempting to generalize the abstract implementation architecture to be
configurable for any learning application that requires networked
collaboration, coaching, and multimedia. Adaptive multimedia [Brusilovsky
et al, 1996] could be included with scripts that automatically generate
HTML pages from the database to meet user's needs. We have designed and
implemented a prototype of this adaptive hypermedia extension but have not
incorporated into our released system. Student modeling facilities would be
improved by informing the Coach of which materials students have examined via
the Tracker.
2.3.2.5
Resource Layer
At this level one describes the system in terms of the resources used and their
performance characteristics, including performance of both hardware and
implemented software, as well as constraints on where that software resides. In
Belz and Luckham's work this level of description is used primarily for
performance modeling,[4] which is not a
concern in this paper. For present purposes the most significant resource
constraints on the implemented architecture are as follows:
In this section we discuss two methods of advice generation that we have
implemented. Syntactic advice strategies make suggestions based solely on the
syntactic structure of students' inquiry diagrams. Consistency-based advice
strategies use a simple knowledge base of consistency relations between
information units to identify information that may challenge or corroborate
relationships postulated by the students. Before describing these advice giving
methods, we first briefly describe the design constraints under which we
operated.
2.3.3.2
Pedagogical Constraints on Advice
Our design of the advisors to be discussed were guided in part by the following
constraints.
Maintain the student-initiated character of Belvedere's environment. Belvedere encourages reflection by allowing students to see their argumentation as an object. They can point to different parts of it and focus on areas that need attention. They can engage in a process of construction and revision, reciprocally explaining and confronting each other. An advisor should not intervene prematurely in their thinking process. It should be discreet, offering advice on request. Students should feel free to discard an advisor's suggestions when they believe them to be irrelevant or inappropriate.
Address certain parts of the task that are critical to the desired cognitive skill. Research on "confirmation bias" and hypothesis driven search suggests that students are likely to be concerned with the process of constructing an argument for a favored theory they are supporting, sometimes overlooking or discounting discrepant data [Klayman & Ha 1987; Chinn & Brewer 1993]. Also, they may not consider alternate explanations of the data they are using. An advisor should address these problems. For example, it should offer information that the student may not have sought, including information that is discrepant with the student's theory.
Be applicable to problems constructed by outside experts and teachers.
The advisor should be able to give useful advice based on a simple knowledge
base that an expert or a teacher might construct. So far Belvedere has been
used to construct arguments in domains as different as theory of evolution,
contrasting theories of mountain formation, cause of the Cretaceous
extinctions, whether HIV causes AIDS, and theories in social psychology. It is
not feasible to develop for each a representation of the knowledge needed to
deal with the argumentation students potentially could engage in. We are
instead interested in a general approach, applicable to all the cases, in which
the knowledge base can be constructed by a teacher.
2.3.3.3
Syntactic Advice Strategies
The first approach we implemented gives advice in response to situations that
can be defined on a purely syntactic basis, using only the structural and
categorical features of the students' argument graphs. (The students' text is
not interpreted.) Types of advice are defined in terms of patterns to be
matched to the diagram, and textual advice to be given if there is a match.
Example advice patterns are given in Table 1.
The advice applicable to a given inquiry diagram is often more than a student can be expected to absorb and respond to at one time. When more than one instance of advice is applicable, a preference-based quicksort algorithm is used, following a mechanism used by Suthers [1993] for selecting between alternate explanations. Advice instances are sorted in priority order, and the highest priority advice is given. Objects that bind to variables in the patterns are highlighted in yellow when the advice is given, so the user can easily identify what the advice is about. If further advice is requested before the diagram changes, subsequent advice instances on the sorted list are used without reanalysis. We are investigating preferences that take into account factors such as prior advice that has been given, how that advice has been responded to, how recently the object of advice was constructed, and various categorical attributes of the applicable advice.
We believe that the most important kind of advice is that which stimulates and scaffolds constructive activity on the part of the students. To give this kind of "open world" advice, our first step was to identify partial argument patterns in the inquiry diagram the students had constructed so far and indicate how the student could complete these patterns. For example, the advisor might find theoretical claims that have no empirical support and suggest that support be sought (hypothesis-lacks-empirical-evidence), or it might find competing theories that are both supported by the same empirical evidence, and ask if there is a discriminating piece of evidence (discriminating-evidence-needed in Table 1).
(def-advice 'HYPOTHESIS-LACKS-EMPIRICAL-EVIDENCE
:query '(retrieve (?h) (and (hypothesis ?h) (No-Evidencep ?h)))
:advice ("Can you find data that are for or against this hypothesis?
A scientific hypothesis is put forward to explain observed data. Data
that a hypothesis explains or predicts count *for* it. Data that are
inconsistent with the hypothesis count *against* it.")
:subsequent-advice ("Can you find some data for or against this
hypothesis?")
:advice-types '(incompleteness))
(def-advice 'DISCRIMINATING-EVIDENCE-NEEDED
:query '(remove-duplicate-binding-sets
(retrieve (?h1 ?h2)
(and (hypothesis ?h1) (hypothesis ?h2)
(:not (:same-as ?h1 ?h2))
(Exists-Consistent-DataP ?h1)
(Exists-Consistent-DataP ?h2)
(fail (Consistent-HypoP ?h1 ?h2))
(Identical-EvidenceP ?h1 ?h2))))
:advice ("These hypotheses are supported by the same data. When this
happens, scientists look for more data as a \"tie breaker\" -- especially
data that is *against* one hypothesis. Can you produce some data that
would \"rule out\" one of the hypotheses?")
:subsequent-advice ("Can you produce some data that might support just
one of the hypotheses?")
:advice-types '(incompleteness evaluative))
(def-advice 'CONFIRMATION-BIAS
:query '(retrieve (?h) (and
(hypothesis ?h)
(Exists-Multiple-Consistent-DataP ?h)
(Multiply-LinkedP ?h)
(fail (Exists-Inconsistent-DataP ?h))))
:advice
("You've done a nice job of finding data that is consistent with this
hypothesis. However, in science we must consider whether there is any
evidence *against* our hypothesis as well as evidence for it. Otherwise
we risk fooling ourselves into believing a false hypothesis. Is there
any evidence against this hypothesis?")
:subsequent-advice ("Don't forget to look for evidence against this
hypothesis!")
:advice-types '(cognitive-bias))
(def-advice 'ALTERNATE-HYPOTHESIS
:query '(retrieve (?h) (hypothesis ?h))
:lisp-test '(lambda (client query-result)
(declare (ignore client))
(= (length query-result) 1))
:advice ("Scientists consider many hypotheses to get the best
explanation of the data they are interested in. If they don't compare
their favorite idea to other ideas, somebody else will! Is there another
hypothesis that you could consider?")
:subsequent-advice ("Is there another hypothesis that you could
consider?")
:advice-types '(cognitive-bias incompleteness))
(def-advice 'SWALLOW-DOES-NOT-A-SUMMER-MAKE
:query '(retrieve (?d ?h)
(and (data ?d) (hypothesis ?h)
(Consistent-HypoP ?d ?h)
(fail (Exists-Multiple-Consistent-DataP ?h))
(fail (Exists-Inconsistent-DataP ?h))))
:advice-template
("Strong hypotheses and theories usually have a lot of data to support
them. However, this hypothesis has only one consistent data item. It
looks rather weak. Can you find more data for this hypothesis? Can you
find data that is against it?")
:subsequent-advice
("This hypothesis has only one consistent data item. Could you find
more data for (or against) this hypothesis?")
:advice-types '(evaluative incompleteness))
The syntactic advisor also responds to illegal and incoherent constructions. "Illegal" constructions are those that use elements of the diagrammatic language in a manner inconsistent with their intended semantics. For example, a "support" link should not be used between data. "Incoherent" constructions are those in which the elements are each used legally, but in combinations that are semantically problematic. Examples include a loop of "support" links, or a datum that both supports and undermines the same claim. Some other advice given includes:
The consistency-based advisor is our first step in this direction. It is intended to offer specific information that the student may not discover on her own. It makes two assumptions: students construct their inquiry diagrams from existing units of text, and these units are annotated with relationships recording whether they are consistent or inconsistent with each other, based on expert judgment. The advisor searches the latter "consistency graph" to find paths between units that students have used in their inquiry diagrams, and selects other units found along those paths which are brought to the students' attention. Our claim is that this enables us to point out information that is relevant at a given point in the inquiry process without needing to pay the cost of a more complete semantic model of that information.
When the teacher or domain expert defines the task and the information needed, she can draw an inquiry diagram in Belvedere. The diagram is easily transformed into a set of consistency relations between pairs of texts, following the rules described above. These relations become the "expert model" or knowledge base for the consistency-based advisor.
During a student session, students can drag texts authored by the expert into their diagrams, and express argumentation relationships between them. The links in the student diagram are interpreted as consistency relationships in the manner described above. The advisor can then compare consistency relations defined by the students with consistency relations defined by the expert, and look for inconsistencies and other possible advice. The comparison is based on a graph-search algorithm, which has been implemented and tested as reported below. It searches in the expert's consistency graph for paths between nodes that have been related in the students' graph, constrained by the following rules:
Rules 2 to 4 are used to maintain the consistency of the path. Once a negative link is crossed, it is plausible that the two nodes at the end of the path are inconsistent. We cannot extend the path any farther, because whatever conclusion is drawn from there is quite arbitrary. For example, suppose that A is inconsistent with B, and B is inconsistent with C. We can't conclude that A is inconsistent with C: they could be consistent components of an argument against B. On the other hand, we can't assume that A is consistent with C: they could be arguing against B based on incompatible assumptions. Thus, Rule 4 forces the search to stop when a conflict is reached. Rule 5 is introduced to address the confirmation bias.
We have presently encoded extensive domains of documents on two topics into HTML-based materials databases: What caused mass extinctions? and What advice should be given to a person with a family history of a genetic disorder? The Mass Extinctions database, for example, contains about one hundred snippets. A student or teacher would select a pre-configured "snippet" from an HTML document while browsing the materials database using the Netscape browsing tool. Once such a snippet has been selected, a Java-based "applet" is activated that notifies the Belvedere client tool that the snippet has been selected. A visual icon known as the "In-Box" in the Client is highlighted, indicating that the material from this snippet can be relocated into the inquiry diagram. A list of such selections is maintained in this In-Box. Students also have the option to discard snippets present on the In-Box list. A dialogue box is again provided in which the student can check the snippet summary and modify its type, if necessary. When the student retrieves the snippet from the In-Box, the student-written label (summary) appears in the appropriate hypothesis, data, or principle shape as defined by the student.
The student cannot see the expert diagram during a session. The expert diagram is thought of as a "read-only" entity and is configured by the teacher before an inquiry session begins. The student diagram is dynamic; each time a change occurs in a student diagram, the change is noted by the expert coach and the LOOM knowledge base is updated with the new information.
As students construct an inquiry diagram, they may include snippets from the materials database. The expert coach is utilized only when a student assigns a relationship between two snippets with a "for", "against", or "and" link. The expert coach can only provide advice about what it knows. Thus, if non-snippets are introduced into the student diagram the expert coach will be unaware of their existence, and it will have no advice about non-snippets created by the students. In that case, the argument coach still subjects the non-snippet objects to analysis and can respond. Meta-rules manage the advice from two different coaches before the advice is passed on to the student. As advice is generated from each coach, it is maintained on a list which is then subject to a recursive multi-keyed "preference" sort. For instance, expert advice is provided first, multiple instances of the same advice are reduced to single instances, and argument advice is sorted according to type, ranging from "getting started" (e.g., the inquiry diagram is empty) to "advanced" (e.g., a swallow does not a summer make). In this fashion, we envision future arbitration schemes to manage several such knowledge sources.
The expert coach has been implemented with a best-first heuristic search to determine the optimal path from the start node to the goal node in the expert diagram using the cost function
f(n) = g(n) + h(n)where g is the distance of the path from the current node n in the graph back to the start node, and h is a heuristic estimate of the distance from the current node n to the goal [Cohen 1989]. The heuristic is articulated as follows: If the student has indicated a "for" link, all paths in the expert diagram which contain "against" links will be given shorter distances than paths with "for" links. Likewise, if a student has indicated an "against" link, all paths in the expert diagram which contain "for" links will be given shorter distances than paths with "against" links. In this fashion, as the best-first queue is sorted in non-decreasing order, the shorter paths will be sorted according to distance to the beginning of the queue and be favored at each new iteration of the search. The following rules also constrain the search of the expert coach:
Although we have selected an appropriate level of representation, the snippet,
to allow the student to access domain-relevant material, we are considering the
pedagogical value of both a finer and a coarser grain size. A finer grain would
reduce ambiguity and increase the accuracy of feedback. On the other hand, a
coarser grain, i.e., at the level of a normal paragraph, or of a typical Web
document, would enable quicker authoring of the Web-based materials described
earlier. Currently the expert's specification of the relations is a major
bottleneck for complex domains. The model of coaching with a larger grain size
would be an "FYI" coach, which would function like a research librarian
forwarding new information to those likely to be interested in it. It would
still be possible to specify "for" and "against" relations in a general sense,
just as a paper can give evidence for or against a particular view. However,
coarse-grained representation has obvious limitations. For example, it is
important for students to learn that one can often extract evidence for a view
from a context that is generally unfavorable. Indeed, scientific papers are
obliged to take note of divergent views and limitations. We are also
considering exposing the student to sub-graphs of the expert diagram. We are
exploring models of learning and cognitive/perceptual mapping for the novice
and expert, regarding the information realized in the diagrams the web-based
materials [e.g., Petre 1993].
2.3.4
Design of Classroom Implementation
Technology has the potential to transform education, not just by providing
students with an opportunity to learn the tools of the modern workplace, nor
simply by automating aspects of the educational process. Its greater potential
lies in the ability to change the organization of classes, from
teacher-centered didactic instruction to student-centered collaborative inquiry
[Cummins, 1988; O'Neill & Gomez, 1994; Scardamalia & Bereiter, 1991].
Properly designed technology supports and facilitates collaborative approaches
to learning that are recommended by numerous researchers [Johnson &
Johnson, 1989; Kuhn, 1993; Slavin, 1990; Webb, 1989]. However, this potential
is not an attribute of technology in itself. Computer supported collaborative
learning (CSCL) technology will have an impact only if it is designed along
with methodologies and materials that provide support for teachers who are
learning to implement nontraditional activities in their classrooms, and
address concerns such as integration with the curriculum and effective
utilization of inadequate computer resources. In this section we describe the
support we provided.
Consistent with these views, pilot studies with Belvedere [Suthers &
Weiner; 1995] indicated that there was a need to structure the roles and
activities of students working with Belvedere (see also [Waugh & Levin,
1988]). With DoDEA teacher colleagues, we developed a classroom implementation
methodology focused on collaborative problem solving by small groups of
students. The methodology calls for changes in the classroom environment,
teacher's role, curriculum materials, student activities, and assessment
methodology. Students work in teams to investigate real-world "challenge
problems," designed to match and enrich the DoDDS curriculum with attention to
National Science Education Standards [National Academy of Sciences, 1996]. The
teams plan their investigation, perform hands-on experiments, analyze their
results, and report their conclusions to others. Our classroom activity plans
provide teachers with specific guidance on how to manage these activities with
different levels of computer resources. Teachers and students are provided with
assessment instruments designed as an integral part of the curriculum.
Assessment rubrics are given to the students at the beginning of their project
as criteria to guide their activities. They guide peer review, as well as
helping the teacher assess nontraditional learning objectives. In this section
we describe and comment on this methodology as it was carried out in our most
exemplary case, in a Wurzburgh general science class.
2.3.4.1
Classroom Environment
The traditional teacher centered environment was changed to one that is more
suitable for group work. Five computer stations and five tables for hands-on
investigations were set up around the classroom. The computer stations became
the center for collaborative exploration of Web-based curriculum materials, use
of computer simulations and data analysis tools, and use of the Belvedere
environment for recording results and their significance. The tables became
centers for experiments with hands-on manipulatives and for paper-based work,
including peer review. In less technology-rich environments, students can share
work across time periods by successively working on and storing diagrams.
2.3.4.2
Teacher's Role
The teacher shifted toward the role of facilitator of student inquiry, moving
among workstations, guiding student work and offering individual help.
Teachers' transition into this new role was supported by involving them in the
development of student activity plans for their classes during our STS2 teacher
training workshop. Teacher involvement provides a sense of ownership, helping
to motivate the change in how they facilitate learning, and customizes the
plans for different classroom contexts. We provided additional support in a
form of cognitive apprenticeship [Collins, et al. 1989], by conducting
several classes with Belvedere activities ourselves. The teacher assumed
increasing responsibility over time, both within each class and across classes.
Where developer modeling is not available, electronic discussions and peer
mentoring may help teachers support each other in new practices.
2.3.4.3
Curriculum Materials
Students learn to conduct critical inquiry by being posed with real world
problems. Towards this end, we developed Web-based curriculum modules,[5] treating controversial issues such as
genetic testing, or scientific problems under active investigation such as mass
extinctions. The modules take into account the National Science Education
Standards [National Academy of Sciences, 1996], local curricular standards, and
teacher suggestions. The modules present students with authentic problems in
which good solutions require consideration of multiple viewpoints and the use
of evidence collected from various sources of information.
Figure
6. Web-based Materials for Challenge Problem
As shown in Figure 6, two menus are provided with the web based materials. A
domain independent menu (left side) guides students through five phases of
inquiry, providing suggestions on how to conduct scientific inquiry and how to
use the Belvedere software in this process. Another menu (bottom) provides
domain specific links organized in a manner relevant to the phases of inquiry.
For example, students are provided with a link to a glossary of terms; access
to simplified versions of articles on scientists' hypotheses, methodology, and
field reports; and a link to experiments involving both hands-on manipulatives
and computer simulations. The Web-pages contain "reference" icons resembling
text pages (two are seen in Figure 6, one preceding each paragraph of text),
which enable students to send text found on these pages into the inquiry
diagram's "in-box."
2.3.4.4
Student Activities
In our exemplary case, the activities began with ourselves or the teacher
modeling the use of inquiry diagrams to the whole class, using a simple
everyday example such as reasoning about why a friend's coat is wet. Then
groups of 4-6 students were formed, each working with a computer. After
exploring background information on the science problem and choosing hypotheses
to investigate, each group was divided. One pair or triad of students conducted
hands-on experiments, recorded their results, and discussed findings. The other
pair or triad of students continued to investigate the computer based articles
and simulations. The full group then reassembled in front of their computer to
share the results of their work, and record the results and interpretation of
their experiences in their inquiry diagrams (e.g., Figure 1). Finally, the
student team prepared a written report to be presented to other teams. In a
one-computer classroom, computer access can be interleaved with hands-on
activities.
What you learn How you learn it How you tell how well you learned
to do
Poor The inquiry diagram contains one
appropriate hypothesis and no
related data.
To formulate Create Belvedere Fair The inquiry diagram shows one
and revise inquiry diagrams appropriate hypothesis and one
scientific that record data supporting it.
explanations, different Good The inquiry diagram shows one
and to use hypotheses about hypothesis with the use of
evidence to a problem, evidence for it as well as against
it.
develop a different data Good The inquiry diagram shows several
logical that can help hypotheses each connected to
argument. you decide multiple pieces of data.
between
the hypotheses, Great The inquiry diagram shows multiple
and the hypotheses with the use of
relationships evidence for as well as against
between the data each of these hypotheses.
and hypotheses.
Great The inquiry diagram indicates
additional information the student
would look for to support or to
refute explanations.
Poor The inquiry diagram only contains
information that is drawn from
personal experience or speculation.
To develop a Find out what Good The inquiry diagram contains
model that specialists in references to information from
integrates different only one discipline, for example
concepts from disciplines Geology, Physics, Chemistry, or
think of the Biology.
problem.
multiple Look for Good The information in the inquiry
domains with information from diagrams come from one kind of
different kinds different resource, for example only from
of data. resources, such experiments, field observations,
as on-line and or articles.
library Great The inquiry diagram contains
articles, references to information from
experiments you multiple disciplines such as
do, and field Geology, Physics, Chemistry,
observations. Biology.
Great The information in the inquiry
diagrams are drawn from multiple
resources, such as experiments,
field observations, and articles.
Application Model
Abstract System Model
Interaction Model Conceptual Model
Abstract Implementation Model
Resource Model
Figure 8. Architecture Reference Model.
The Architecture Reference Model is hierarchy of "architectural abstraction
levels" that appear to be useful for developing and organizing architectures of
advanced educational software applications, including computer-aided
instruction (CAI), intelligent learning environments (ILE), and intelligent
tutoring systems (ITS). It is a descriptive and modeling tool, but is
not itself an architecture. Different kinds of concepts and components
are used for defining architectures at each level of the hierarchy. Each level
represents a different way of thinking about an architecture. A given system
would have a complete description at each level. The levels are illustrated in
Figure 8 and summarized below.
Subsequently, we added the Belvedere system and Argumentation Coach (left side
of Figure 10). Belvedere's communication architecture (abstracted in Figure 10
as the "BORBI" but described more fully in section 2.3.2.4) is itself capable
of supporting component-based composition of functionality. However, we decided
to use the MOO due to its prior use in the first demonstration. Integration of
the Belvedere subsystem into the MOO required the addition of one translator
component (the other small box in the figure): no modification to Belvedere
itself was required. The translator watched the MOO for Hypothesis and
Simulation Run objects sent by the Simulation Interface. When seen, these were
converted to Belvedere Hypothesis and Data objects and placed in the user's
"in-box" for consideration.
2.3.5.2.2
Lessons Learned from the Integration Demonstration
From this experience we learned a number of lessons. First, the open
client-server architectures of Active Illustrations and Belvedere greatly
facilitated composition of the learning space. Second, semantic
interoperability is a significant issue. Much of our communications during
development were in effect a process of negotiating an informal shared
ontology. The process may have been more efficient and involved fewer
misunderstandings if a standard ontology or even reference vocabulary were
available and known to all. However, we realized that ontologies could not
address the fundamental mismatch between systems with different
representational requirements. For example, the Active Illustrations simulation
and Simulation Interface communicated in terms of individual parameter settings
that define a simulation run, while the Belvedere evidence mapping facility
needed to treat each entire simulation runs as a single empirical unit. Third,
translators are part of the solution: they enable components to use their own
representational systems and still communicate. Fourth, there are semantic
"coupling" issues that translators cannot solve. This requires more
explanation. We initially considered placing the burden of solving this problem
on the Belvedere-MOO translator, to avoid the need to modify any of the
components or their interfaces. The translator would aggregate individual
parameter setting and simulation run events into "data" objects that record the
results of the run. These data objects would then appear automatically in
Belvedere's in-box. However, focusing on the needs of the learner, we elected
to follow a different approach, for three major reasons. (1) Not all simulation
runs will be informative enough to use. We wanted to avoid cluttering the
in-box with many not so useful objects. (2) We wanted to encourage the learner
to reflect on which runs were worth recording, by requiring that the learner
make the decision of which to record. (3) The learner needs to make the
connection between her experiences in the simulation environment and the
representational objects that she manipulates in Belvedere. Hence the
aggregated objects representing simulation runs should be created and given
visual identities recognizable to the learner while still in the simulation
environment. The Simulation Interface already enabled the user to provide
textual labels for simulation runs. We modified the Simulation Interface to
provide a facility for broadcasting labeled simulation run summary objects to
the MOO (and hence to the Belvedere in-box), thereby enabling the learner to
select relevant results without leaving the simulation context. We also added a
similar facility for hypotheses created in the Simulation Interface.
This experience illustrates some tradeoffs and limitations of a purely "plug
and play" approach to component based systems, while also showing that there is
hope given further research. We showed not only how to reduce the effort
required to "hook up" diverse components, but also the value of sharing
semantics between applications. Information objects created with empirical and
theoretical identities in one application (Active Illustrations) retained that
identity in how they were treated in another application (Belvedere and its
Argumentation Coach). Furthermore, a third Tutor Agent treated these objects as
having the same semantics in both situations. Consistent treatment of the
learner's representations by different software agents reinforces the semantics
that we want learners to reflect upon and manipulate. Perhaps most
significantly, the contextual semantics of these objects accumulate as
they are used: an object, viewed in one context (e.g., evidence maps), "stands
for" the learning interactions centered on it in another context (e.g., the
simulation) Critical to this accumulation of contextual semantics is
persistence of identity. Special attention was required to ensure that
the learner "sees" the thing that shows up in Belvedere as the same object she
constructed in Active Illustrations.
2.3.5.3
Workshop: Architectures and Methods for Designing Cost-Effective and Reusable
ITS
While supported by CAETI funding, the author of this report organized (with
Brant Cheikes, Neil Jacobstein, and Tom Murray) a workshop at the 3rd
International Conference on Intelligent Tutoring Systems (ITS'96), entitled
"Architectures and Methods for Designing Cost-Effective and Reusable ITSs".
This highly successful workshop attracted over 40 international participants,
several of whom were CAETI-funded, and led to subsequent fruitful
collaborations. Five working groups were formed: Exploring Industry-Standard
Architectures; Communication Architectures for ITS Components, Shared
Vocabularies for Representing Pedagogical Knowledge, ITS Shells and Generic
Task Domains, and Using the World Wide Web to support ITS. Further information
on this workshop can be obtained from http://advlearn.lrdc.pitt.edu/.
2.4
Results
2.4.1
Highlights of Project
2.4.1.1
Cognitive/Education Highlights
Extended configuration to be available early 1997 , including inquiry
diagrams, concept maps, causal loop diagrams, influence diagrams, and plan
diagrams, will extend applicability to other phases of critical inquiry as
well as other applications beyond education, including risk assessment,
planning, and job skills analysis.
2.4.1.7
Venues and Collaborations
Observations of student activity show that students were engaged and on task during the collaborative problems solving situations presented to them by the Belvedere comprehensive approach. Teachers indicated that the approach enhanced students ability to engage in collaborative tasks.
"Classroom observations of teachers and students using Belvedere show that it is being used to support cooperative problem solving, with students working in groups of 2 to 4 students. Students appeared to be engaged and on task. Teachers report that it is easy to use, and they find that it enhances students ability to engage in cooperative work, and to address scientific hypothesis testing in an organized and analytical way."[9]Students also found the activity structure easy to follow and helpful in integrating work with the use of various software tools and information resources such as the world wide web.
"Students report that working with Belvedere makes it easier for them to organize and review the arguments for and against a specific scientific hypothesis. They also report that they find it easy to integrate work in Belvedere with work in other applications like Word and Excel and Web Browsers. Students using Belvedere generated artifacts that demonstrated integration of the knowledge representation maps generated using Belvedere with text and graphic information taken from a variety of resources, including the Internet, and with numerical data generated as a result of classroom activities."Teachers reported that the staff development activities provided were adequate for classroom implementation of the Belvedere approach.
"Data collected on the efficacy of staff development for teachers using Belvedere indicated that they were very satisfied with the training provided, and believed that they were well prepared to integrate use of the Belvedere software into their classrooms. The staff development provided for Belvedere compared very favorably with that provided by other application developers in the CAETI program.The independent evaluator also reported a striking difference in classroom organization before and after the introduction of the Belvedere approach. The classroom changed from a traditional format, with students doing work at their desks in rows, to a group-centered organization, in which students were gathered around computers or hands-on activities "like campfires" and engaged in active discussion.
Many of our conclusions are to be found throughout this report, especially in
Section 2.3.2.6 (Architectural Lessons), 2.3.3.5 (Coaching Status and Future
Directions), and 2.3.5.2.2 (Lessons Learned from the Integration
Demonstration). Other conclusions are best reported in the form of
recommendations for future work.
2.6
Recommendations
We present first recommendations for further work on the Belvedere software and
supporting materials towards a deployable system, and then recommendations for
future research of a more general nature.
2.6.1
Follow-on Work for Belvedere
The following work is be recommended to further the development of Belvedere as
a deployable application.
2.6.1.1
Port Server to NT
Although our Belvedere inquiry diagram software can run "stand-alone" without a
server, a server is required to support (a) collaboration over the network, (b)
a persistent database, and (c) a local Web-site containing customized materials
and student and teacher pages. Hence we strongly recommend continuation of the
client/server model. The currently delivered system uses a Netra (Unix) server.
Unix was chosen for development because of its strength as a large-scale server
platform, and because of the availability of free tools. However, recognizing
DoDEA's need to deliver on platforms for which there is ongoing administrative
support, we began to redesign and reimplement our server to enable delivery on
other server-class machines such as Windows NT. This work should be continued:
The more familiar of the two approaches is technology transfer to a commercial entity which would market and support a product derived from research software such as Belvedere. One barrier towards such technology transfer is the lack of regular contact between researchers and relevant commercial entities. Research labs should be facilitated in finding appropriate commercialization options.
An alternate, non-proprietary approach to long term support of educational
software is being developed. This approach is known variously as the
Educational Object Economy (NSF) and the Object Economy Model (Apple Computer).
Reusable, platform independent software objects are shared and maintained in
object repositories. The Repository is based on an innovative licensing scheme
which provides software for free, provided that improved versions are made
available in the repository under the same license, or that a royalty-paying
license be negotiated (royalties fund the repository). We realize that this
model is too experimental at this point to be viewed as a primary delivery
mechanism. However, considerations such as (1) the large number of specialized
topics addressed in education, (2) the need for students to examine the objects
of their study under multiple representations using a variety of tools, and (3)
the propensity for teachers and schools to adopt materials to their own way of
doing things suggest that the traditional commercial economic model will not
support the diversity of functionality needed for education. Hence an EOE model
should be supported.
2.6.2
Additional Research
Summarizing what has been said throughout this document, the following research
directions are recommended.
2.6.2.1
Designing open, interoperable educational software.
Knowledge-based educational systems have historically been large,
self-contained programs with specialized platform requirements. To make these
technologies viable, we must be able add component functionality incrementally,
and enable systems to interoperate with commercial software and Internet
resources. To reduce the cost of materials prepared by developers, and to
enable greater collaboration between users, representations of educational
materials should be shareable between diverse applications across the Internet.
This suggests a "lowest common denominator" approach, yet we do not want to
limit support for more advanced functionality such as domain-specific coaching.
Several lines of work are suggested.
One involves the design of communication architectures for composing systems out of separately developed components. As suggested in this document, key issues lie in semantic interoperability. We recommend a testbed in which learning applications are composed of existing software that fills specific pedagogical needs. The research issues would be to investigate how to get adequate semantic coupling to support the pedagogical needs while minimizing changes needed to the components. Research and development could examine the roles of various solutions, including ontologies, translators, and alternate communication infrastructures. The work should be concerned with both software-level coupling (e.g., agents interpret objects from other components in an appropriate manner) and human-level coupling (e.g., objects retain their identity in the eye of the user as they move between components).
Another line of work involves the development of semantic annotations that can
be embedded in more conventional materials, yet support advanced functionality.
Much interest has been generated recently in the area of "metadata" for digital
learning objects. Such efforts provide part of the groundwork for our vision,
but are limited in three ways. First, the granularity of such efforts tends to
be coarser than would be required for a semantic model of learner-constructed
representational artifacts -- the dominant model is annotation of entire
objects or documents. Second, metadata efforts do not go far enough to provide
machine interpretable content semantics. Shared ontologies could eventually
fill this need. (Metadata efforts are not to be faulted: there is an immediate
need for other aspects of metadata that cannot be delayed while the research
community develops ontologies.) The third limitation of metadata is also a
limitation of any purely formal semantics for learner-constructed
representations: it does not ensure that semantics will accrue for the
user of the materials. Future work may be required in providing objects
with persistence of appearance as well as of behavior before learners
will perceive that which moves between applications as a single thing
accumulating contextual semantics.
2.6.2.2
Representational devices as "epistemic forms" for collaborative
learning.
The design of any software interface entails a large number of design
decisions, more than any one research lab can back up with empirical
investigations. However some design features are so critical to the intended
application that they should receive thorough study. Such is the case with
representational devices used in software for socially-mediated learning (also
known as "computer supported collaborative learning"). We view these
representational devices as "epistemic forms:" tools that guide and coordinate
knowledge-building interactions. We have repeatedly observed that learners who
are provided with a set of representational primitives for the construction of
knowledge artifacts discuss the appropriate choice of primitive for a given
constructive act. Thus, by manipulating the design of the primitives, it is
possible to manipulate the discriminations that learners reflect on. Once
learners have constructed representations, their learning interactions are
further guided by the objects and relationships (expressed or potential) that
these representations make salient. For example, some interfaces for evaluating
theoretical claims with respect to empirical observations represent evidential
relations between instances of these two categories only implicitly, such as
through containment of one inside the other; while others (such as Belvedere)
represent the relations explicitly, such as with arcs in graphs. We claim that
this difference whether the relationships are represented as first class
objects will have a significant effect on learners' discussions about
these relationships.
These kinds of design considerations are critical, yet are insufficiently
studied. We recommend a series of studies that vary features of
representational systems, such as whether epistemological distinctions
(theoretical claims versus empirical observations) must be attached to
statements, and whether evidential relations between statements are represented
as first class objects. Dependent variables include coding of discussion for
certain discourse features shown by other literature to be correlated with
positive learning outcomes, as well as direct measures of individual learning
outcomes in both subject matter knowledge and inquiry skills.
2.6.2.3
Software participation in reflective learning interactions
.
Collaborative learning can yield positive results such as increased motivation,
greater learning, and transfer of knowledge to related tasks. However,
collaboration alone does not guarantee learning gains. For example, learners
cannot model expert knowledge and performance for each other. The design of
effective representational tools, although helpful, does not solve this
problem. Although we may design tools that make certain aspects of a problem
more explicit, learners may yet fail to notice these aspects or know how to act
on them in an appropriate way. A major advantage software environments for the
construction of representations (over paper, for example) is that this medium
is interactive and computational. Software can be designed to selectively enter
into the reflective dialogue, helping learners recognize the critical features
displayed in the representations and respond with constructive activity.
However, this requires that the design of representational devices and their
formal semantics be coordinated with learners' understandings of those
representations. For these reasons we view research on software for automated
advice giving, coaching, etc. as an integral part of research on the design of
representational tools for reflective learning interactions.
A related line of work might first begin with observations of peer coaching to
answer questions such as: What support for learning do peer groups offer their
members, and what support is lacking from peer groups that must be addressed by
some mixture of human and automated mentoring? How can we recognize
opportunities for coaching effective collaboration?
2.6.2.4
Examining the cost-benefit tradeoff between knowledge engineering and coaching
functionality.
Knowledge-based techniques for advising or coaching typically require
representations of the knowledge of a domain that are used to annotate the
materials manipulated or created by students. However, "knowledge engineering"
requires considerable work on the part of developers. Also, interactions
intended to ascertain the meaning of users' materials may distract them from
the learning task. Hence it is natural to ask what benefit is gained from
automated coaching or advising and how the benefits compare to these costs. We
have taken an incremental approach, investigating the utility of advice
obtained from minimal semantic annotations before proceeding to more complex
functionality. We recommend continuation of this work, using open architectures
such as that reported herein to enable these coaches to be added or removed
independently of each other for experimentation purposes.
2.6.2.5
Designing hypermedia structures to scaffold critical inquiry
skills.
In our preparation of Web-based "field reports," "experiments," "conference
papers," etc. we were faced with apparently conflicting requirements in
designing the hypertext links by which these materials are indexed. On the one
hand, research consistently shows the utility of reifying the cognitive
structures of experts, so that learners can be guided by and more easily
acquire these structures. On the other hand, students need to be faced with
choices similar to those in the real world in order to engage in exploratory
behavior and practice newly acquired cognitive skills. Is there a conflict
between reifying expert structures and presenting students with real-world
choices, perhaps requiring alternate links structures for different phases of
the learning process? We recommend investigations into whether it is necessary
to generate alternate link structures in real time to meet conflicting needs.
2.6.2.6
Scaffolding learning from simulations and visualizations.
This recommended line of work investigates how people learn and fail
to learn from simulations and visualizations. These data analysis and
communication methodologies are widely used by scientists, but perhaps special
skills are needed to leverage their power in learning applications. We
recommend a line of work to (1) identify how people fail to acquire information
that is made available by simulations and visualizations, (2) identify the
missing prerequisite knowledge or skills responsible for this failure, (3)
design interface aids and coaching that assist with these prerequisites, and
(4) evaluate whether this assistance improves the effectiveness of simulations
and visualizations as a means towards other learning ends.
2.6.2.7
Comparing scientists' and learners' inquiry skills.
Our own work would have benefited from studies of whether scientists' expertise
includes domain independent inquiry skills that could be taught to school
children. We recommend studies that separate domain-specific from
domain-independent aspects of expertise by comparing scientists and novices
working in domains unfamiliar to both. A hypertext information-gathering
environment and Belvedere could be used to record subjects' use of the
information they deem relevant. One might record and analyze information
seeking and use in terms of dimensions such as systematicity of search, and
whether and when subjects seek disconfirming as well as confirming evidence.
2.6.2.8
Realistic school implementation of advanced educational
technology.
Our experience implementing Belvedere in four Department of Defense Dependent
Schools has highlighted several problems concerning the scale-up of prototype
advanced technology efforts to schools. Although some problems require
political and economic solutions, others may be amenable to research in
advanced technology and professional development supporting its use.
Designing teachers' mental models of our systems. While conducting teacher development workshops, we found ourselves engaged in cognitively demanding, rapid translation of our rich mental model of the software into a model that would be useful to teachers. We now believe that we need to design a mental model of the system oriented towards its classroom implementation, and to do so as part of the software design process rather than after the fact. This need fits nicely with user-oriented layers of a hierarchical architecture reference model that that developed in collaboration with external colleagues Frank Belz and Tom Wheeler.
Large scale, distributed evaluation. In order to conduct our research
in the context of large scale school implementations, we need ways to
understand what is going on during possibly concurrent use in a number of
geographically distributed classrooms. Methodologies for analyzing large sets
of interaction data will be needed to augment what can be observed in person.
Our networked technology provides an opportunity for distributed data
collection and developing new evaluation methodologies.
3.
End Matter
3.1
Appendices
Software and HTML materials are appended in the form of a CD-ROM (which also
includes this report). The electronic version of this report will include
hyperlinks to the following: