Traditional architecture of Intelligent Tutoring Systems (ITSs) does not offer sufficient modularity. There is a lack of open distributed ITS architectures, despite ITSs being systems that may need frequent changes due to the modifications of particular course or adaptation to new courses. The chapter focuses on usage of distributed technologies in development of open ITSs to increase the modularity of the ITSs and facilitate the implementation of needed changes into ITSs. The aim of the chapter is to propose open and highly modular ITS architectures, using two distributed paradigms – intelligent software agents and services.
To realize intelligent tutoring various types of learning materials and problems have to be presented to the learner, moreover it should be done intelligently enough to successfully simulate the human tutor. Thus all known ITSs concentrate on a certain problem domain or course to provide specific functionality for problems and examples of the domain. For example, the system has to be capable to analyse learner’s actions during the problem solving. Each new type of problems needs corresponding code to handle it. Problemsdiffer from course to course and may change if the course is changed. As a consequence the functionality of ITS may be modified to adapt to the changes in the course or to a new course. The system should be open for certain types of components handling new types of problems, materials, feedback, etc. The architecture of ITS should support such an openness.
ITSs traditionally have modular architecture consisting of four modules, namely tutoring module, expert module, student diagnosis module and communication module (Grundspenkis & Anohina, 2005). The main principle is to build components using only one type of knowledge (pedagogical knowledge, domain knowledge and knowledge about the learner). As a result, the architecture does not have sufficient modularity for complex ITSs. To facilitate modularity and change management distributed technologies like services and agents are used in ITSs. Well known examples of agent based ITSs are Ines system for nurse education (Hospers et al., 2003), Formal Languages and aUTomata Education system FLUTE (Devedzic et al., 2000), IVET virtual training environment (de Antonio et al, 2005) and WADIES – a Web- and agent-based adaptive learning environment for teaching compilers (Georguli et al., 2003). Grundspenkis and Anohina (2005) have concluded that agent based ITSs mainly implement traditional modules as sets of agents. The authors have defined customizable set of agents that implements the system as a set of distributed components and at the same time maintains the traditional idea of ITS’s modules separating different types of knowledge. Nevertheless, there is a need for a distributed architecture, because the set of agents only defines ITS components and does not solve architectural problems of ITSs.
As of author’s knowledge no specific service oriented architectures (SOA) for ITS development exist, except the ones presented further in the chapter. The only known distributed ITS architectures are a few multi-agent architectures for ITS development. These architectures mainly consist of agents from the set of agents defined by Grundspenkis and Anohina. The architectures are closed in the sense that system’s functionality can not be changed just by adding/removing agents from the system. Examples of such architectures are ABITS (Capuano et al, 2000), IVET (de Antonio et al, 2005) and X-genitor (Triantis & Pintelas, 2004). Several open architectures are proposed to allow adding new student agents and create a learning environment for multiple learners, for example, JADE (Silveira & Vicari, 2002) and two level multi-agent architecture for distance learning environment (Webber & Pesty, 2002). Still, these architectures are open only for new student agents to join the system and are closed for any other types of agents. As a consequence there is a need for architectures enabling usage of all advantages of distributed technologies, including the possibility to change system’s functionality by just adding and/or removing distributed components from the system. The chapter describes such ITS architectures. The remainder of the chapter is organized as follows. Intelligent tutoring systems gives a brief introduction to ITSs by describing the tutoring process carried out by ITSs and presenting the traditional architecture of ITSs. Agent based intelligent tutoring systems is dedicated to agent based ITSs. It analyses the related work about the agent based ITS architectures and describes open holonic multi-agent ITS architecture. Intelligent agents and web services compares intelligent agents to web services. It analyses the lessons learned in the development of holonic multi-agent architecture and possibilities to apply them to SOA. Service oriented intelligent tutoring systems describes service oriented ITS architecture that implements each module as a set of services. Hybrid intelligent tutoring system architecture proposes hybrid architecture that includes both agents and services. Agents implement higher level deliberative components while services realize lower level reactive components. Conclusion concludes the chapter.
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