A Web-based User Adaptive Learning Environment Anneli Edman, Andreas Hamfelt, Sabine Koch, Ina-Veronika Wagner Department of Information Science Uppsala University Box 513, S-751 20 Uppsala, Sweden e-mail:
[email protected],
[email protected] Abstract We present a design structure for constructing web based user adaptive learning environments. Currently the web offers huge amounts of unstructured information but no facilities for exploiting this in a problem solving situation. Our aim is to gather and present information from the web, based on specific user needs and in accordance with pedagogical theory concerning learning situations. The proposed design structure strives to incorporate in a principled manner knowledge concerning the user, the current problem to be solved, the gathering and presentation of the related information from the web in a user adapted fashion and finally, but most importantly, the interrelations between all these notions. 1. Introduction Currently the web provides access to enormous amounts of information but in such an unstructured manner that the user is subject to what has been referred to as the information flood [Miyahara & Okamoto, 1997]. Existing approaches to find solutions to this problem are advanced search engines, using push techniques or exploiting agents and metadata. Nevertheless, information retrieval from the Internet is far from being satisfactory today: Context and domain independent search engines tend to overload the user with data he/she did not look for; even the experienced user is overcharged typing advanced queries which do not seem to follow any standard. In other words, Internet retrieval is very time consuming and ineffective. Hypermedia systems, such as the web, are not designed to be used as pedagogical tools. The design is merely focused on information retrieval than learning [Whalley, 1993] and learning is not the same as retrieving information [Hammond, 1993]. A hypermedia system offers material to be viewed but there is no guarantee that the user adopts a productive strategy for understanding and learning from this material. In this paper we present an approach focussed on particular knowledge domains where problem solving and other pedagogical principles are central aspects for communicating the information residing on, for instance, a web site. Experiences from automatising reasoning within such domains indicate that it is vital to adjust the presentation of the system’s knowledge to the current user category according to pedagogical principles. Currently we are pursuing a project within the medical domain, the aim of which is to formulate medical case descriptions in a standardized way, using so called controlled subsets of natural languages directly mappable to full first order logic. The language used is Attempto Controlled English (ACE) [Fuchs, Schwertel & Schwitter, 1999a, 1999b], which allows the domain specialist to express medical texts in familiar natural language and combines this with the rigor of formal languages thus enabling for quality assured medical text documentation. The benefit is firstly that patterns can be defined for describing medical cases in a uniform way avoiding ambiguity and vagueness. Secondly, since the informal descriptions are directly mapped to a formal theory the same medical cases can be written in controlled versions of different natural languages with
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the identical concepts of the respective vocabularies coupled and to some extent be automatically compared. A third benefit is that the formalization may effectively function as a knowledge-based system, from which additional information can be obtained through inferencing such as deduction, abduction and induction. The principal ambition of this paper is to inspire discussions concerning a proposal for a design structure for constructing web based user adaptive learning environments. The system architecture in question has been successfully implemented for local knowledge based hypermedia as reported in [Edman & Hamfelt, 1999]. Now, the architecture is to be elaborated to a more general setting where knowledge can reside also remotely e.g., on other web sites. Thus it should be able to gather and present information from the web, based on specific user needs and in accordance with pedagogical theory concerning learning situations in relation to problem solving. Introduced here as an elaboration of the notion of metadata, metaknowledge could be used to support more advanced presentation of the content of a web site according to pedagogical principles. Ultimately, the proposed design structure strives to incorporate in a principled manner knowledge concerning the user, the current problem to be solved, the gathering and presentation of the related information from the web in a user adapted fashion and finally, but most importantly, the interrelations between all these notions. The proposed architecture has been designed to facilitate meeting pedagogical needs that will be illustrated below with support for individual learning by: - Mixed initiative between the user and system. - Bottom-up and top -down learning by means of rule abstraction. - Encouragement to activity through problem solving. - Offering several perspectives on a problem in contrast to the single perspective offered by a textbook. The paper is structured as follows. In Sect. 2 is introduced to the proposed architecture. Next in Sect. 3 a sample domain is presented which in Sect. 4 will serve to illustrate how the architecture can be exploited for meeting pedagogical needs in controlled language domains. Finally in Sect. 5, after accounting for related work, we conclude. 2. The Proposed Architecture Theoretically, an information system can be conceived of as a constellation of three ‘theories’. Firstly we have the informal information about the domain expressed in some informal way say natural language, secondly there is the formal theory amenable for computation and thirdly the metatheory which relates these two theories. The metatheory is often neglected but performs a rather important role. The metatheory is responsible for the performance of the system as a whole and should account for completing the system’s information in various ways e.g., from the user, other web sites or whatever context the system resides in. Traditionally, a web site is a static source of information. In contrast, a dynamic web site would be capable not only of displaying its content but also of reacting to external requests. For instance, it would be desirable that, when accessed by an agent, the site could dynamically present its information tailored to a user profile specified by the agent. In our case, the natural language textual descriptions of medical cases are directly mapped to a formalisation. This in itself provides a rudimentary reactive capability since an agent can query the knowledge base for implicit knowledge rather than just collecting the text. However, in order to tailor the knowledge to specific user needs and pedagogical recommendations,
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metaknowledge is necessary for selecting, modifying and composing appropriate presentations. Moreover, the metaknowledge is responsible for completing the knowledge of the web site by itself querying the user and agents accessing other web sites. To accommodate for the requirements defined above, we propose that web sites should be constructed according to an information system architecture that does not blur but instead clearly brings out the different categories of information, that is to say the informal theory, the formal theory and the metatheory. In previous work we have developed an architecture for knowledge based hypermedia [Edman & Hamfelt, 1999]. The assumptions underlying that architecture were as follows. Knowledge based systems and hypermedia systems are flip sides of the same coin [Rada & Barlow, 1989]. A complete formalization of a domain seldom is feasible. Therefore, in a knowledge-based system it is necessary to co-operate with the user in the problem solving. To enable the user to provide adequate knowledge, the system must be capable of communicating also informal knowledge expressed on various media to the user. This can be regarded as providing an informal context to the knowledge system as elaborated in [Edman & Hamfelt, 1997]. The system must contain formalized knowledge concerning how to present this informal knowledge. Such a formalisation resides on the metalevel with respect to the formalization of the domain and the informal descriptions of the domain. So as to enhance the user’s understanding of the domain it is critical that the metalevel theory is formulated in accordance with pedagogical principles. In Fig. 1 the formal theory is a representation of the domain knowledge, the informal theory a description of the same domain in some informal medium. The metatheory is responsible for composing a presentation from data available in the informal theory and for managing inferencing with the formal theory. The metatheory communicates with the user who provides case specific interpretation of the informal knowledge. Moreover, the metatheory can reflect over the formal theory and extend it either by user input or by inferencing such as deduction (implicit logically implied knowledge), abduction (adding facts) and induction (extracting rules) etc. In [Edman & Hamfelt, 1999] we describe how this architecture is implemented in metalogic programming. USER The user's interpretation The metatheory's
of context identifies the
presentation of context.
implicit part of the metatheory
Metatheory
transferring from the informal to the formal.
formal
informal
The metatheory's formal
The metatheory's formal
reasoning about the
reasoning with the formal theory,
informal theory in
known formulas are directly used,
order to present the
new formulas corresponding to
system's context.
the user's interpretation (the context) are identified.
Informal
text(Obj,X,T1).
concl(Obj,A)
