North American Web Developers Conference, October 1998:

A Pedagogical Basis for Adaptive WWW Textbooks

Dr Richard Pascoe - Adrian Sallis
Otago University, New Zealand - Otaru University of Commerce, Japan

ABSTRACT

The World Wide Web is the perfect medium for the distribution of electronic textbooks. While it is relatively easy to build HTML pages to store the content, there are pedagogical and design issues that must be taken into consideration if the electronic textbook is to be of real value.

Electronic textbooks can be designed to allow the content presented to the student to be adapted according to the manner in which the student interacts with the textbooks. Such systems are referred to as adaptive hypermedia or more generally adaptive courseware. Brusilovsky et al. (1998, page 298)argues that by developing such systems, users with very different backgrounds, prior domain knowledge and learning goals can find adaptive courseware more accessible to less prepared and less motivated students, than traditional electronic or printed textbooks.

In the first section of this paper a pedagogical foundation is described with issues focusing on the learning process. In the second section is examined some of the most important components of adaptive media systems and examples are given of a few methods of adaptive navigation. In the last section of the paper a description is given of the authors' ongoing development of WIT, a WWW Intelligent Tutoring System based upon the pedagogy described.

Keywords:Pedagogy, Adaptive, WWW, ITS, Learning, Hypermedia, Courseware

Introduction

Recently, the World Wide Web (WWW) and the Internet have become important tools in distance teaching. The WWW enables timely distribution of educational documents, often referred to as electronic textbooks, in which content is presented using a wide variety of media (hypertext, graphics, animations, audio, video, and so on). The Internet, on the other hand, has increased the range of facilities (electronic mail, newsgroups, video conferences, and so on) with which teachers and students can communicate, both synchronously and asynchronously. Together, the WWW and the Internet have enriched both the classroom and distance teaching environments.

Traditionally, printed textbooks are chosen by the teacher for a variety of reasons. Most prominent of which is the comprehensive, detailed manner in which material taught in the course is presented in the textbook. Such decisions are also influenced by the teacher's expectation of the background knowledge for the `typical student'. Where the presumed level of background knowledge is low, for example, a more introductory textbook will be chosen; conversely, a more detailed, in depth textbook will be chosen where background knowledge is presumed to be high. Generally, the most careful and informed selection will not, however, result in a single printed textbook which suits all students in a particular course.

Currently, electronic textbooks provided through the WWW are designed along the same traditional lines. That is, the textbook is written according to the teacher's presumed level of background knowledge of a typical student participating in the course. However, having the textbook in an electronic form, rather than on the printed page, provides an opportunity to tailor or adapt the textbook's content according to the perceived background knowledge of each student interacting with the electronic textbook. In effect, there is an opportunity to provide background material to those students who are identified as needing supplementary material, without boring other students with greater background knowledge. Conversely, more advanced content can be presented when more knowledgeable students are identified.

Electronic textbooks which adapt the content presented according to the manner in which students interact with the textbooks are referred to as adaptive hypermedia or more generally adaptive courseware. InterBook is an example of a tool for authoring and delivering adaptive electronic textbooks on the WWW which has been used with in areal-world teaching and learning context for a group of twenty-five second year education students in their study of databases and spreadsheets; (Brusilovsky and Ekland, 1998).

Brusilovsky et al. (1998, page 298) argue that 'the progress in Web-based education is related to the development of adaptive courseware which can accommodate users with very different backgrounds, prior knowledge of the subject and learning goals and which can guide the user adaptively through the course.' In essence, they suggest that adaptive courseware is more accessible to less prepared and less motivated students, than traditional electronic or printed textbooks.

In this paper, the authors discuss a pedagogy in terms that can be linked to well defined components of adaptive hypermedia and potentially components of Intelligent Tutoring Systems. In doing so, the author's intention is to harness the advantages of both the WWW and the Internet, and the educational support offered by computing. The paper is concluded with discussion of the author's ongoing development of WIT, a WWW Intelligent Tutoring System based upon the pedagogy described for use in a university environment.

Pedagogy

For the purpose of this discussion, learning is viewed as a process by which a student refines their understanding of concepts and terms being considered. The term `refines' is used in preference to `acquires' because at any point in time, a person will be improving upon their existing or background understanding of the concepts and terms being considered. Simplistically, the goal of learning is for unfamiliar terms and concepts to become meaningful to the student. This style of teaching is similar to that referred to as Hermeneutics:

The essence of the Hermes or hermeneutical tradition has been to ensure that "something foreign, strange, separated in time, space, or experience is made familiar, present, comprehensible; something requiring representation, explanation, or translation is somehow 'brought to understanding'"; (Palmer(1969) as quoted by; Webb (1996, pg 37))

Learning is achieved either indirectly through interaction with a teacher in a teacher centred environment, directly through personal experience and exploration in a student centred environment, or through a mixture of both. Ideally, each person should adopt that style of learning which is best suited to their background and personal preferences. In this discussion, learning is divided into 4 components:

Evaluation: where measurement is made of the student's understanding of the concepts and terminology, and of the extent to which objectives and goals set for the learning process have been achieved.
Reflection: where consideration is given by student and teacher to motivation, goals, and objectives of the learning process, and, in a practical sense, to the specific concepts and terminology to be understood;
Planning: where learning activities linked to specific concepts and terminology are defined. Examples of activities that may be defined are: reading particular texts; group discussion; a collection of exercises linked to concepts and terminology; and so on; and
Action: where the learning activities are performed with the intent of refining the understanding of the concepts and terms being considered and achieving the goals and objectives of the learning process.

The authors suggest that these 4 components occur, either implicitly or explicitly, regardless of whether learning is accomplished within a teacher or student centred learning process. In a teacher centred learning process, both students and teachers are likely to reflect in some form upon the learning process, each arriving at potentially different educational goals and objectives. The planning and evaluation components are more likely to be driven by the teacher.

In a student centred environment, reflection by the student is expected to significantly influence, if not completely control, the planning and evaluation components of the learning process. However, the opportunity for a student to pursue all or some of their goals and objectives is constrained as a consequence of learning within an externally defined framework with predefined educational goals. For example, a second year course may have prerequisite understanding developed during one or more first year courses and itself promote the development of prerequisite understanding for one or more third year courses.

Evaluation of the student's understanding may lead to further reflection by either the teacher, the student or both, and revised educational goals and objectives. In essence, the participants adapt the learning process in accordance with their observations of the results from evaluation. This adaption may involve changes to: the educational goals and objectives; the plan, in order that the student explores either different levels of content detail or the same concepts using different learning activities; or the techniques used to evaluate the student's understanding in case the technique itself influences the evaluation.

The learning process is regarded, therefore, as an ongoing, cyclic, and dynamic process directed towards achieving the initial, and any subsequent, educational goals and objectives defined. There are clear similarities between the learning process described here and the notion of action research. Both comprise reflection, planning, action, and evaluation (referred to as observation in action research), and both processes are cyclic (the notion of the Lewinian spiral; (Kemmis and McTaggart, 1988, pg.8)).

In the next Section, a brief description of adaptive hypermedia will be given. In this description, based upon that of Brusilovsky (1996), the major components of adaptive hypermedia will be explained and subsequently linked to the elements of the pedagogy described in this Section.

Adaptive Hypermedia

Information presented in a WWW page by an adaptive hypermedia system may vary from visit to visit according to what other pages and activities the user may have seen or performed between these visits. Any variation in information shown in a WWW page is determined by the system in accordance with rules defined by the author of the WWW pages. Although there are many components to an adaptive hypermedia system, there are three of particular interest here: the domain, the user model, and the adaption embodied within the system.

Domain

The domain is the area or topic for which adaptive hypermedia, and adaptive electronic textbooks in particular, are intended as a resource. The concepts and terminology associated with a domain is referred to as domain knowledge. In practice, concepts are explained in individual HTML documents (or tagged sections within a single document) which are connected by hyperlinks to reflect the relationship among the concepts being explained. The concepts and their inter relationships form a semantic network which describes the structure of the domain knowledge.

User Model

The User Model is at the heart of an adaptive hypermedia system because information within the user model is processed to determine the best way of adapting the hypermedia for this user. The user model is a collection of characteristics for which specific values are recorded for each user of the hypermedia. In general, these characteristics relate to user preferences, goals, and knowledge. Brusilovsky (1996) identifies five characteristics which are commonly included in user models of existing adaptive hypermedia: users' goals, knowledge, background, hyperspace experience and preferences. Of these, he identifies user's knowledge as the most important feature in current implemented systems.

User's knowledge is most often represented by the overlay model, where for each domain concept a value indicative of the user's understanding of this concept is maintained in their user model. Another representation is the stereotype model, where several distinct 'stereotypical' user categories are defined, and, at any point in time, a user is regarded as belonging to one of the categories for a particular area of knowledge. Clearly, the user's knowledge will change as they explore the hypermedia resource provided. Accordingly, the user model will also change over time to reflect the evolution of the user's understanding of the domain knowledge.

Information contained within the user model can be obtained in three ways. First, the user can explicitly state values for characteristics in the user model in much the same way as many software packages allows the user to specify the colour of hyperlinks, the size and typeface of the text. At the other extreme, the adaptive hypermedia system observes the user's behaviour or interaction with the hypermedia and from these observations the system derives values for the user model. In between these two extremes is the notion of collaborative user modelling where both the system and the user cooperate in providing information for the user model.

In practice, user observations may be a record of what parts of the hypermedia the user has visited and the order in which these visits occurred. Other observations may be in the form of the success or otherwise that a user has when performing various exercises, such as multi-choice questions, to evaluate their understanding of concepts being explained.

User modelling is a difficult task which largely determines the quality with which the hypermedia adapts to the needs of particular users. The same is true in real life teaching situations where placing oneself into the students frame of reference in order to clarify their misunderstanding of a concept is very difficult.

Adaption

Adaption is essentially a definition of what parts of the hypermedia can be adapted, and under what circumstances this adaption is to occur. Brusilovsky (1996) discusses 7 adaptive techniques which are divided into two groups: content adaption and link adaption.

When considering presenting domain knowledge to users the designer must take into account the form that the material will be presented in. Using the WWW, designers can present material to users in a number of ways. Some of these forms are HTML, PDF documents, audio, pictorial, movies and interactive diagrams. With access to a number of representations of the same information users have the choice of picking the format that they prefer most and consolidating their knowledge by cross referencing. Ideally the system will take the users preference into account when presenting new material to the user.

Central to hypermedia are the hyperlinks used to connect associated elements within the document. Adapting the presentation of these links is a method of supporting the user's navigation through the document. By convention once a hyperlink has been used the colour of the link changes (typically from blue to red). Brusilovsky (1996) defines 5 styles of link adaption:

Direct guidance: where the system decides what is the most appropriate part of the document would for the user to visit, and creates a link to this, and only this, part of the document;
Adaptive ordering of links: where the order of the hyperlinks shown on the page is determined by information contained within the user model and by some 'user-valuable criteria.' (op cite, pg 103); those hyperlinks at the top of the list are judged by the system to be the most appropriate for the user at that point in time. Later, after the user has viewed more of the document, this ordering may differ from what was originally presented. This unpredicatablity is a known weakness of this style of link adaption;
Adaptive hiding of links: where links made available to the user are only those relevant to the user's current goal or objective, or appropriate to the user's current level of understanding. This is the most frequently used style of link adaption;
Adaptive annotation of links: where the links are decorated, either textually or graphically, with additional information indicative of the relevance or suitability of the material being linked. Changing the colour of the link is an example, and using a traffic light icon showing a red light indicates that the content linked is irrelevant or unsuitable at this point in time, whereas a green traffic light indicates that the linked material is appropriate;
Map adaption: where the structure and form of navigation maps are altered in accordance with information contained within the user model.

Many of the link adaption styles are demonstrated by the InterBook tool for authoring and delivering adaptive electronic textbooks on the WWW.

Synthesis of Pedagogy and Adaptive Hypermedia

**Table 1:** Linking elements of the proposed pedagogy with elements of an adaptive hypermedia system
	Adaptive Hypermedia Technology
Pedagogy	Domain	User Model	Adaption
Reflection		Information added to the user model	As the student interacts with the system store the information and provide further material for the student to reflect upon.
Planning	consideration of what resources are provided for individual domain concepts	Use of information in the user model	Provide different levels of presentation and present it in different formats. Adding new links for reference navigation.
Action	Reading and interacting with presentation of domain knowledge	Updating the user model	Provide interactive help and examples.
Evaluation		Updating the user model	The use of dynamic tests that differ for the student and the domain.

In this section are discussed issues arising from explicitly linking a particular pedagogy to generic technologies used within adaptive hypermedia. In Table 1 are presented some comments on how elements of the pedagogy presented in Section 2 are associated with elements of adaptive hypermedia discussed in Section 3. To fully utilise the advantages of an adaptive hypermedia document such as an electronic textbook, the author needs to:

provide supplementary material for known problem areas of the domain knowledge. This material is for those students whose background knowledge is below that presumed by the teacher.
provide different versions of the documentation for domain concepts. These versions may be graduated in terms of the complexity or depth of the material presented, or involve the use of different delivery techniques (audio, video, animations, and so on).
design any exercises in such a way that an incorrect answer to a multi-choice question, for example, will have clearly identifiable supplementary material to which the student can be directed to clarify their misunderstanding. Thus, questions and possible answers need to be carefully designed in order to expose common misunderstandings that the author has observed and for which supplementary material is provided.

Conversely, an adaptive hypermedia system must facilitate the authoring process as much as the delivery process in order for the appropriate connections to be made by the author between the various presentations of domain concepts, the information recorded in the user model, and exercises used to test the user's knowledge.

With increased interest in adopting student centred learning environments, the adaptive electronic textbook may evolve into an electronic learning journal. Consider the following scenario. Initially, a student is given an adaptive electronic textbook with which they are to interact. Over time, their preferences and completion of the learning activities contained within the textbook results in the textbook being adapted to their needs and reflects their overall learning experience. If the student could at some point adopt the role of author, they could further tailor and expand the textbook in what ever direction their personal educational goals and objectives required. For this to occur, the authoring facilities would have to be very user friendly and the system itself would need to be capable of adopting the role of an assistant rather than as a tutor.

To investigate issues associated with designing adaptive hypermedia, electronic learning journals, and more generally Intelligent Tutoring Systems (ITS) from a pedagogical basis, the authors are developing WIT, A WWW Intelligent Tutoring System.

A WWW Intelligent Tutoring System

The Authors a currently involved in developing and ITS system that we have called WIT. The objectives of this project are:

To develop a prototype that adheres to the main functional requirements of an ITS.
Our pedagogical objective for WIT 2 is, therefore, to develop an ITS that provides a group centred learning environment that adapts to group behaviour as well as individual student behaviour.
To minimise the interactions between the client and the server.

Current Progress

We have examined many possibilities for creating an architecture that minimises the interactions between the client and the server while adhering to our other objectives. Our early investigations included using Java applets, CGI, Javascript, and the Java expert System Shell (JESS). Although some of these possibilities were promising they have yet to realise their full potential in assisting us to achieve our objectives. We are currently examining the use of ASP (Active Server Pages) to communicate with an Access database through ODBC, while using forms and embedded scripts on the client for presenting the assessment to the student and verifying the input. So far this has proved the most promising of the techniques examined.

The Next Stage of Development

Further work towards our pedagogical objective by developing course content and provide further scope for development of adaptivity at the group level.

Conclusions

In this paper, a pedagogical basis for developing adaptive hypermedia has been proposed. This pedagogy is divided into four components, reflection, evaluation, planning, and action, and in this way is similar in form to that of action research.

Having a pedagogical basis from which to view the development of adaptive hypermedia enables the teacher and student to enhance the learning environment by clearly linking aspects of the pedagogy with the technology embedded within adaptive hypermedia systems. In doing so, the learning process is made more explicit in terms of the structure of the domain in general and the goals, objectives, background, and preferences of the student.

In conclusion, implicit understanding of the learning and teaching processes need to be made explicit to gain the most from adaptive hypermedia. More effort is required in developing this type of educational resource as the domain knowledge needs to be presented in different ways and at different levels of complexity.

References

Brusilovsky, P. (1996),: `Methods and techniques of adaptive hypermedia', User Modeling and User-Adapted Interaction 6(2-3), 87-129.
Brusilovsky, P. & Ekland, J. (1998),: `A study of user model based link annotation in educational hypermedia', Journal of Universal Computer Science 4(4), 429-448.
Brusilovsky, P., Eklund, J. & Schwarz, E. ( 1998),: `Web-based education for all: A tool for development adaptive courseware', Computer Networks and ISDN Systems 30, 291-300.
Brusilovsky, P., Kommers, P. & Streitz, N., eds ( 1996),: Multimedia, Hypermedia, and Virtual Reality. Models, Systems, and Applications. First International Conference, MHVR`94. Selected Papers, Vol. 1077 of Lecture Notes in Computer Science, Springer-Verlag Inc., New York, NY, USA.
Kemmis, S. & McTaggart, R., eds ( 1988),: The Action Research Planner, Geelong, Victoria: Deakin University Press.
Palmer, R. E. (1969),: Hermeneutics. Interpretation Theory in Scheiermacher, Dilthey, Heidegger, and Gadamer, Evanston, IL: Northhestern Uniuersity Press.
Webb, G. (1996),: Understanding Staff Development, Buckingham: Open University Press.

Richard Pascoe
Dr.
Dept. Information Science, University of Otago
PO Box 56, Dunedin, New Zealand
rpascoe@infoscience.otago.ac.nz

Adrian Sallis
Mr.
Otaru University of Commerce
Otaru 047, Japan
ajsallis@ibm.net

© 1998. The author(s), Richard Pascoe and Adrian Sallis, assign(s) to the University of New Brunswick and other educational and non-profit institutions a non-exclusive license to use this document for personal use and in courses of instruction provided that the article is used in full and this copyright statement is reproduced. The author(s) also grant(s) a non-exclusive license to the University of New Brunswick to publish this document in full on the World Wide Web and on CD-ROM and in printed form with the conference papers, and for the document to be published on mirrors on the World Wide Web. Any other usage is prohibited without the express permission of the author(s).