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Article Excerpt
The ultimate aim of this research is to specify and implement a general authoring framework for content and knowledge engineering for Intelligent Educational Systems (IES). In this context we attempt to develop an authoring tool supporting this framework that is powerful in its functionality, generic in its support of instructional strategies and user-friendly in its interaction with the author. The framework that we offer is an ontology-based authoring environment, since we see the use of ontologies as effective means to have structured content and knowledge engineering. The key contribution of our research is the meta-level Authoring Task Ontology (ATO) specifying authoring tasks, goals and activities, and knowledge about the process of engineering IES. It enables us to enable the specification of "evolutional" authoring support system, as a meta-authoring tool that defines and controls the configuration and tuning process of an authoring tool for a specific authoring process. The role of ATO is to help the IES authoring system to "evolve" by defining such a meta-tool, which "knows" the system's ontological structure. In our approach it works analogously to an authoring tool when it generates a concrete learning support system. The ATO also provides a shared vocabulary between all system components, and allows for better interoperability in a modularised architecture. In this way we have the benefit to monitor and assess the authoring process, and to prevent and solve inconsistencies and conflicting situations. Through ontological engineering, a computational formalization of the intelligent systems authoring, we also give our scientific contribution to the in-depth understanding of what the authoring process is.
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INTELLIGENT EDUCATIONAL SYSTEMS AND THEIR AUTHORING
Intelligent educational systems (IES) have proven to be useful and have obtained a significant place in the field of courseware. As authoring of IES is the subject of this article we take a closer look at their authoring aspects. In the analysis of various educational systems (Brusilovsky, 1995; Mizoguchi, Ikeda, & Sinitsa, 1997; Murray, 1999), such as SmartTrainer (Chen, Hayashi, Kin, Ikeda, & Mizoguchi, 1998), AIMS (Aroyo & Dicheva, 2001), InterBook (Brusilovsky & Eklund, 1998), and AHA! (De Bra & Calvi, 1998), we observe that providing user-oriented instruction shows different aspects that are relevant to an author, for example, subject domain modeling, user modeling, instructional and learning strategies, sequencing and structuring the learning material and its maintenance.
The authoring process implies the construction of applications in this IES format. Building an IES requires a lot of work and often it is done from scratch. The current way of designing an IES offers little space for the reusing or sharing of content, knowledge, and functional components. A central problem in maintaining the popularity of IES and benefiting from wide use of IES in practice, is the fact that the current approaches for building IES are rather inflexible and not efficient. The high and dynamic user demands in many aspects of software production are influencing research in the field of intelligent educational software as well (Major & Ainsworth, 1997). The ultimate problems are related to keeping up with the constant requirements for flexibility and adaptability of content and for reusability and sharing of learning objects and structures (Devedzic, Jerinic, & Radovic, 2000) Another problem in current IES research is that assessment of the existing systems is difficult as there is no common reference architecture, nor standardized approaches.
Many researchers in the field of educational systems have been focusing lately in the field of authoring systems and their improvement (Kiyama, Ishiuchi, Ikeda, Tsujimoto, & Fukuhara, 1997; Redfield, 1997; Vassileva, 1995). It is now well known and proven that the popularity of IES and other knowledge-based learning support systems strongly depends on the usability and easy maintenance of their authoring systems (Brusilovsky, 1995). Although the research field has already identified the main requirements for the authoring of IES, still only very application-dependant ones exist and these do not focus on reusability neither of the development efforts, nor in terms of the applicability in different domains (Murray, 1999). As the application domains are multiple and serve various needs, the benefit of a common reference architecture would be significant.
On the positive side, we see that currently a considerable amount of the research on knowledge-based and intelligent systems focuses on concepts and ontologies (Devedzic, 2001; Mizogcuhi & Bourdeau, 2000; Vasilakos, Devedzic, Kinshuk, & Pedrycz, 2004) and focuses on knowledge sharing and reusability (Chen, Hayashi, Kin, Ikeda, & Mizoguchi, 1998; Ikeda, Seta, & Mizoguchi, 1997). In general, an ontology is used to define the basic terms and relations in the domain. Next to this it also provides axioms as rules and constraints for manipulating and managing the terms and their relations within this common domain vocabulary. Ontologies allow the definition of an infrastructure for integrating intelligent systems at the knowledge level, independent of particular implementations, thus enabling knowledge sharing (Breuker & Bredeweg, 1999). Together with various reasoning modules and common knowledge representation techniques, ontologies can be used as the basis for development of libraries of shareable and reusable knowledge modules (which take the form of software components) (Aroyo & Dicheva, 2002; Aroyo, Dicheva, & Cristea, 2002). As a consequence this research that focused on ontologies, offers tools and technologies for the reusing and sharing of knowledge and hence helps intelligent educational systems move towards semantics-aware environments (Aroyo & Dicheva, 2004).
So, when we observe that many of those knowledge-based instructional systems share common architecture features, and we have the recent results in the use of ontologies, then we conclude that it has become possible to specify a reference architecture for concept-based intelligent educational systems. In this way we can allow for a more structured and common approach in the authoring process, as well as supporting the automation of the authoring activities.
AUTHORING SUPPORT
Our reference framework provides the functionality to bridge the gap between author and authoring system in two directions (in line with evolutions in the related research areas): managing the increased intelligence and the need for (conceptual) user-friendliness.
First, we look at the increased intelligence. Authoring of IES is a process with an exponentially growing complexity and it requires many different types of knowledge and considering various constraints, requirements, and educational strategies (Nkambou, Gauthier, & Frasson, 1996). Going towards a process of (semi)-automated IES authoring we need to have explicit representations of strategic knowledge (rules, requirements, constraints) to be able to reason within different contexts and situations within the authoring process. Authoring systems provide a common framework (in terms of functional syntax and semantics) to be instantiated with the needs and requirements of different types of educational systems.
Second, we consider the conceptual distance between user and system. From the analysis of the current state of the art of the educational systems research (Mizoguchi & Bourdeau, 2000; Redfield, 1997) it appears that there is a deep conceptual gap between authoring systems and the authors. The authoring tools are neither intelligent nor user-friendly. Special-purpose systems provide extensive authoring guidance, but the disadvantage here is that changing such systems is not easy, and the knowledge and content can hardly be reused for other educational purposes (Murray, 1999). All this leads to the requirement that the authoring tool should offer the user the possibility to configure or tune the complexity and obtain an autonomous performance of authoring tasks. Structured guidance and feedback to the authors in the complex scale of the design process is also needed.
Our framework is the basis for the development of such an authoring tool. Our ultimate aim is to attain seemingly conflicting goals: to make an authoring...
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