MEDIT: A Web-based environment for advanced ... - CiteSeerX

MEDIT: A Web-based environment for advanced pedagogical issues

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O. Abou Khaled, N. Karacapilidis, Y.A. Rekik, C. Vanoirbeek Department of Computer Science (DI-LITH) Swiss Federal Institute of Technology (EPFL) IN Ecublens, 1015 Lausanne, Switzerland e-mail: faboukhal, karacapi, rekik, [email protected] .ch

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Abstract. MEDIT is a research project that deals with the development of a Web-based environment for various pedagogical issues. Its primary scope is to oer complementary support to all actors involved, and not substitute traditional practices. Our approach distinguishes a set of virtual workspaces and provides the appropriate services for each of them. In addition to a generic hypermedia authoring system, we have implemented advanced tools for multiple view representation of a course, creation and maintenance of customised courses, argumentative discourse and group decision making, the aim being to stimulate information exchange, interaction, and collaborative work among the actors involved. The project is currently under evaluation through two undergraduate courses in the Swiss Federal Institute of Technology. Keywords: computer-aided tutoring and learning, World-Wide Web, distributed and collab-

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orative learning environments, hypermedia authoring system, discourse and group decision making.

1 Introduction

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The use of World-Wide Web as a platform for instructional and learning environments receives much attention the last few years, mainly due to its communication framework and associated facilities for representing, storing, exchanging, searching and accessing multimedia information. The design and implementation of an ecient and eective Web Based Training (WBT) system, however, is not a straightforward task. It relies on a comprehensive problem modeling and an appropriate use of the underlying information and communication technologies [5]. Despite the attractive perspectives, there are various technical diculties that concern the production of multimedia information to be shared by a variety of users and applications, ecient information retrieval facilities, reuse of existing pedagogical material, management of communication between the users, and design of user-friendly interfaces (not to mention other problems such as quality assessment, intellectual property rights, etc.). Furthermore, such an approach raises social issues related to whether it will be accepted and understood by the actors involved, since it drastically changes traditional teaching practices. Most of these aspects are currently addressed by the hypertext community in various research projects, the major problems involved when designing an educational hypertext system being the conceptual linking of documents, user-friendy interfaces and customised production and access to pedagogical material [4]. The current trend is obviously towards the development of open hypermedia systems that encompass Web technologies [2] and integrate groupware tools, originally coming from the Computer-Supported Cooperative Work (CSCW) discipline [3], [8]. Most of WBT systems aim at providing an integrated framework that oers remote edition and hyperdocument management facilities, incorporates communication tools (such as electronic mail) and addresses speci c educational needs (such as self training, tools for evaluations of learning, etc.). For example, World Wide Web Course Tools (WebCT, see http://homebrew1.cs.ubc.ca/webct/) and CourseInfo (http://courses.lightlink.com/web/index.htm) propose interactive quizzes; Lotus Learning Space (http://www.lotus.com/home.nsf/tabs/learnspace) and TopClass (http://www.wbtsystems.com/) oer the possibility to create a virtual classroom; CyberProf (http://www.vpaa.uillinois.edu/Al-

the.95/summaries/hubler.html) and WebCT provide tools to track and evaluate students and classes. The simple integration of existing tools is not sucient. Production of computer based teaching material to be both accessed and viewed in an interactive way is an important issue [14]. Ecient organisation of document bases for multi-user activities is another [13]. In line with these issues, ARIADNE is a european project that aims at de ning, implementing and testing methodologies for the proper use of telematics-based solutions for academic education and certain types of corporate training [7]. A system for managing electronic documents, namely the Knowledge Pool System, has been speci ed, which is based on a pedagogical indexation scheme. Other aspects addressed are the course assembly and delivery. MATILDA is another information framework that considers the above issues by separating the information domain from the application one and thereby aims at promoting information reuse and a \cleaner" identi cation of information structure [11]. MEDIT (Multimedia Environment for Distributed Interactive Teaching) is a research project taking place in the Swiss Federal Institute of Technology (Jan. '97-Dec. '98) that aims at developing a Web-based environment for a variety of pedagogical issues [1]. The project intends to oer complementary support to traditional practices and not to replace them. Using our environment, teachers and students may cooperate on a variety of course-related activities (i.e., lessons, exercises, informal discussions, etc.), and are able to work with multimedia documents using a Hypermedia Authoring System implemented for the needs of the project. Our system oers most of the services provided in the abovementioned systems and research projects. However, the originality of our approach lays on the use of highly structured documents that results in an ecient management of all document classes. For instance, from the same set of course documents, MEDIT can provide two classical views (by chapter and by session), but also a new one, namely the semantic view. It also allows a student to create and maintain his customised course. This does not only permit for attaching annotations to an existing document (like in Web Course, http://www.madduck.com/index.html), but for integrating course documents according to his preferred way of learning. In addition, arguing that tutoring environments require appropriate mechanisms for motivating and structuring discussions through collaborative work [10], [12], our system provides an advanced tool for discourse and decision making between teachers and students. The rest of the paper is organised as follows. Section 2 highlights modeling issues in our project; we describe the actors and roles involved, the services provided, and the organisation of a webbased tutoring environment. Section 3 discusses in detail advanced pedagogical issues addressed in the system, namely multiple view course representation, student customised course, and group discussion and decision making. Finally, Section 4 concludes the paper with a preliminary evaluation of the system and future work plans.

2 Modeling a web-based pedagogical environment During the design phase of the project, we had a lot of discussions with a variety of experts and users involved in the pedagogical domain (instructors, students, cognitive psychologists, computer scientists, etc.). One of the rst tasks during the development of the project was to identify the actors involved and services required in a tutoring and learning environment. Furthermore, we have distinguished a set of course-related activities, the idea being that each of them is often associated with dierent actors and/or services and, therefore, dierent tools are needed. This partition was based on the concept of virtual workspaces. The proper speci cation of the above concepts and their relationships was a prerequisite for the implementation of the system.

2.1 Actors and services In a teaching environment, the basic actors are certainly teachers and students. A basic actor can produce or consume information. In the rst case, he is responsible for generating and organising the documents (choosing the appropriate layout and formats), while in the second one he is seeking information for various purposes (research, review, consulting, etc.). Use of Web-based technologies involves numerous technical and administrative problems which have to be addressed by another

actor, the system manager. Furthermore, in web-based group discussion and decision making tools, like the one our system provides, the various argumentation elements inserted by the basic actors need rst to be \checked" by a discussion moderator whose role is to assure that elements were inserted to the right position in the corresponding discussion graph (see Section 3.3), check cognitive and comprehensibility issues of such elements, etc. The services provided are classi ed as follows: { authoring services: They concern a variety of document classes and the basic actors. Our environment provides appropriate authoring tools for teachers to edit and organize their courses (based on contents, semantics, etc.), exercises (questions, quizzes, simulations, etc.), and collections of information (bibliography, announcements, links, etc.), while for students to resolve exercises, perform examinations, organize private workspaces, etc. { information access and retrieval services: They provide multiple views of documents, and navigation and search mechanisms for all document classes (courses, exercises, articles, etc.). They also concern the exchange of documents and usual problems arising from dierent document formats and contents type. { communication and collaboration services: These include features provided in the group discussion and decision making tool, news, mailing lists, and FAQs. { Management services: These are related to the organisation and storage of documents, documents' coherence, access rights, communication protocols, etc. They have been often jointly addressed with the services of the above categories (for instance, in most cases authoring involves coherence management and access right de nition). Keeping in mind that the eectiveness of tutoring and learning systems can be seriously reduced by a badly conceived interface, much care was given to the design of the Human Computer Interaction of our environment. This is associated with the proper Web Interface Design and Usability Engineering [1]. The former has to take into account the speci c features of the platform, such as the totally customized information access. The latter should aim at assessing the system's suitability for a task and determining whether the user's needs are met.

2.2 Virtual work and communication spaces

After multiple interviews with the main actors and experts in the teaching domain and in order to ful ll their requirements, we developed an architecture based on working spaces decomposition. Every workspace deals with speci c teaching services and oers \tailored" tools. It can be viewed as an instantiation of the teaching environment (with its own document classes and tools) to one's speci c teaching context or needs. Each space is further divided in dierent sub-spaces, as shown in Table 1. COURSES EXERCISES COOPERATIVE WORK Multiple View Representation Electronic Homework Newsgroups and Mailing Lists Student Customised Course Logically Structured Exercises Argumentation and Group Decision Making Other Information Quizzes (Multiple Choice Questions) Frequently Asked Questions

Table 1: The MEDIT workspaces.

The majority of existing approaches in web-based tutoring views a course as an indivisible entity, and does not allow the teacher to have a choice of services or a personal con guration of the course. On the contrary, our environment allows him to select the spaces he desires for the course and the corresponding virtual course environment is generated automatically (this incorporates on-the- y creation and compilation of the associated software classes).

3 Advanced pedagogical issues This section reports on advanced issues developed in the context of our project aiming at stimulating information exchange, interaction, and collaborative work between actors. Students are viewed as active actors, i.e., they are not only consumers of information but, on the contrary, they are able to enrich the course through questions, notes and discussions, as well as by generating a customized version of the course. Teachers also take a more active role (than in other current approaches) by participating - together with students - in the discussion forums.

3.1 Multiple course view The course book and notes are the traditional support for a course. The contents of the book are organized by chapter, while the course notes by session. Beyond traditional approaches, that provide a course view by book chapter or session date, MEDIT oers an advanced view based on course semantics, the idea being to reuse the same course contents in order to produce several views. Semantic view allows a reader to select what and how he wants to learn, according to his speci c needs (for instance, to create a personal view of a course that is useful for him to resolve some exercises). Multiple view course representation gives an active role and improves the critical attitude of the students.

Fig. 1.: Creating the semantic view. To create the semantic view, our approach proceeds as follows: The teacher has rst to conceive his view of the course. This task is the harder one for a teacher, and it takes about 10 to 15 days (as argued by most teachers that collaborate in the project). The teacher has then to create a tree-like course representation, based on his conception. MEDIT oers an easy-to-use tool to support this task (Figure 1, left window). Every leaf of the tree corresponds to a course concept, method or de nition. Having nished with this task, the teacher has just to click on a button and the system will generate a set of HTML les corresponding to the tree created (Figure 1, middle window). By selecting such a le, he can then launch an editing tool (Figure 1, right window) and use existing views (by chapter or session) and external information to edit it as he prefers (note that in each such le there is information about the corresponding path in the tree).

Oscillateur généralisé / Dissipatif / Permanent / Energétique

Related Informations - Texts - Links - Images - Exercises

Fig. 2.: Accessing the semantic view. The students may also access the semantic view of a course through the interface shown in the left window of Figure 2 (the choices appearing in this interface are related to the tree constructed

by the teacher and are updated automatically whenever the teacher modi es the tree). The right window of Figure 2 corresponds to what the student has selected.

3.2 Student customised course MEDIT reserves a private virtual space for each student registered for the course. The space remains his property during the semester. It serves like an electronic notebook where he can put his personal notes and documents. The management of the space is totally autonomous for each student. Features involved here are the easy creation, editing and deletion of the space and its components, access protection capabilities, and attachment of annotations and external existing documents (according to dierent views, after searching the Web, etc.). In the example shown in Figure 3, a student browses the course documents both by chapter and session (two top right windows). Having selected a link from one of these windows, the corresponding le appears in the top left window. This le is highly segmented according to a prede ned set of HTML tags (the buttons shown are inserted in the existing documents on-the- y). Finally, the student selects the segments he is interested in, and can preview the le he has been working on so far in the window appearing in the bottom part of the gure.

Fig. 3.: Creating a customised course. The virtual private space makes the student responsible for the content of his course and may improve the quality of learning. Felder [6] has de ned ve categories of students according to their preferred way of learning (namely active, re ective, visual, verbal, and intuitive learners). Our approach is well suited for any of them. For instance, a visual learner may create a course with many gures, tables and images. On the contrary, a verbal learner may mostly use annotations and notes when creating his own space.

3.3 Group discussion and decision making features One of our main objectives in MEDIT is to augment the eectiveness of discussions among groups of students and teachers through the interactive sharing of information between them. Having removed communication impediments using the Web, we aimed at providing techniques for structuring the decision analysis and systematically directing the pattern, timing, or content of such discussions. Among the major issues arising during the development of such a tool are the eective

organization of (usually informal) discourses, and provision of rules and procedures for achieving consistency and automation of data processing. For instance, students usually confront decision making situations when participating in a group project, solving exercises together, etc. In order to reach a solution, they have to examine a variety of alternatives. Con icts among the individual students' suggestions are inevitable and support for achieving consensus and compromise is usually required. Each student may adopt and, consequently, suggest his own approach; opinions may dier about the relevance or value of a proposition when deciding an issue; students may have arguments supporting or against alternative solutions. In addition, they have to confront the existence of insucient and too much information simultaneously. In other words, for some parts of the problem, relevant information which would be useful for making a decision is missing, whereas for others, the time needed for the retrieval and comprehension of the existing volume of information is prohibitive. MEDIT provides an advanced discourse and group decision making tool able to address the above issues. The tool augments classical decision making approaches by supporting argumentative discourse among students and teachers. Its argumentation framework is a variant of the informal Ibis model of argumentation [15]. The argumentation elements provided are issues, alternatives, positions, and constraints representing preference relations. In the sequel, we use a real example about the solution of an exercise given to a group of two students in the context of a Fluid Mechanic course. The actors involved in the discussion, namely the teacher and the two students, bring up the necessary argumentation in order to express their perspectives. The left part of Figure 4 illustrates an instance of the corresponding discussion forum. As shown, our approach maps a multi-agent decision making process to a discussion graph with a hierarchical structure.

Fig. 4.: Discourse and group decision making in MEDIT. Issues correspond to decisions to be made, or problems to be solved (e.g., \Solve exercise No 32"). They are brought up by any type of actor and are open to dispute. Issues consist of a set of alternatives that correspond to potential choices (e.g., \follow the exact method", and \follow the Rayleigh method" belong to , and have been proposed by student-1 and student-2, respectively). Issues can be inside other issues in cases where some alternatives need to be grouped together. Only one alternative in each issue is nally proposed by the system. Positions are asserted in order to support the selection of a speci c solution (alternative), or avert the actors' interest from it by expressing some objection. For instance, \always leads to the exact solution" has been asserted to support , while \it is a rather complicated approach" to express student-2's objection to it. Positions may also refer to some other position in order to provide additional information about it, e.g., \the method is well-documented in the course book" (arguing against ). A position always refers to a single other position or alternative, while an alternative is always in a single issue. issue-1:

alternative-3:

alternative-7:

issue-1

position-4:

alternative-3

position-5:

position-6:

position-5

In decision making environments, one has usually to weigh dierent criteria. Unfortunately, well de ned utility and probability functions regarding properties or attributes of alternatives (used in traditional decision making approaches), as well as complete ordering of these criteria are usually absent. In our approach, constraints provide a qualitative way to weigh reasons for and against the selection of a certain course of action. A constraint is a tuple of the form , where the preference relation can be more (less) important than or of equal importance to. Constraints may give various levels of importance to alternatives. Like the other argumentation elements, they are subject to discussion; therefore, they may be \linked" with positions supporting or challenging them. In Figure 4, : \exact solution vs. computational time" expresses the preference relation \ is more important than " (has been inserted by teacher-1). Alternatives, positions and constraints have an activation label indicating their current status (it can be active or inactive). This label is calculated according to the argumentation underneath and the type of evidence speci ed for them. In general, dierent elements of the argumentation, even in the same debate, do not necessarily need the same type of evidence. Active positions are considered \accepted" due to discussion underneath (e.g., strong supporting arguments, no counterarguments), while inactive positions are (temporarily) \rejected". Similarly, active alternatives correspond to \recommended" choices, i.e., choices that are the strongest among the alternatives in their issue. Apart from an activation label, each constraint has a consistency label which can be consistent or inconsistent. Every time a constraint is inserted in the discussion graph, the system checks if both positions of the new constraint exist in another, previously inserted, constraint. In the armative case, the new constraint is considered either redundant, if it also has the same preference relation, or con icting, otherwise. A redundant constraint is ignored, while a con icting one is grouped together with the previously inserted constraint in an issue automatically created by the system, the rationale being to gather together con icting constraints and stimulate further argumentation on them until only one becomes active. If both positions of the new constraint do not exist in a previously inserted constraint, its consistency is checked against previous active and consistent constraints referring to the same element (or belonging to the same issue). Argumentation in our framework is performed through a variety of discourse acts. These acts may have dierent functions and roles in the argumentative discourse. We classify them in two major categories: agent acts and internal (system) acts. Agent acts concern user actions and correspond to functions directly supported by the user interface. Such functions include the opening of an issue, submission of an alternative, etc. Internal acts are functions performed by the system in order to check consistency, update the discussion status and recommend solutions. These functions are called by the agent acts and are hidden from the end user. A full description of the mechanisms for calculation of activation and consistency labels are beyond the scope of this paper (for a detailed presentation see [9],[10]). The argumentation framework suggested in this paper combines concepts from various wellestablished areas such as Decision Theory, Non-Monotonic Reasoning, Constraint Satisfaction and Cognitive Modeling. As a stand-alone module, it can act as an assistant and advisor, by recommending solutions and leaving the nal enforcement of decisions and actions to the participants. The system platform used facilitates access to the current knowledge by making available all relevant data and documents. When highlighting an argumentation item in the upper pane of the Discussion Forum window (Figure 4, left), all related information is given in the lower pane. By clicking on the entry, the associated HTML le appears in a new window. In our example, exercise No 32 is fully described in the right window of Figure 4. [position, preference relation,

position]

constraint-9

position-4

position-8

Url

4 Discussion MEDIT aims at providing modern pedagogical support using the so-called New Information and Communication Technologies (NICT). Emphasis was given on how such an approach may aect the relations between students and teachers, and enhance the services oered in a traditional course framework. To address these objectives, our environment is based on a decomposition of course workspaces and provides an advanced hypermedia system for each of them. In addition,

to stimulate an active participation of the actors involved, tools for multiple view representation, private workspaces and group discussion and decision making have been integrated. The system is currently under evaluation through two undergraduate courses (Fluid Mechanics and Vibratory Mechanics) with the participation of 6 teachers (2 professors and 4 assistants) and about 50 students (20 and 30 in the above courses, respectively). A system introduction (it takes less than an hour for students and about three hours for teachers) was sucient to get the users acquainted with it. A member of our development group supervised and assisted the users during their rst try. The feedback we have received so far was very positive. Teachers admitted that the authoring environment is easy to use (locally or remotely), and appreciated the fact that they can still use their preferred editors to create the required course documents, while students liked the idea of having their own private work spaces. Both teachers and students liked the ideas of course decomposition, multiple views and group discussion forum, and have admitted that the proposed environment certainly stimulates information exchange, interaction and collaborative work. Future work directions include tracking of the student acts during the creation and maintenance of their private work spaces to extract valuable information about their pro les, interests, and learning attitudes. This information will aid the teachers to re-evaluate their course conception, design of exercises and projects, and in general, their course environments. We also intend to work further on the group discussion and decision making tool to provide assistance to the students during their participation in a project. The idea is to aid them constructing robust arguments and, consequently, nding the right solutions through the consideration of \similar cases" which could be retrieved from previous projects, course documents, Web information, etc.

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