studying the mental processes that are dedicated to the processing of information in the brain and mathematical models were used to try and explain human abilities, the field of artificial intelligence emerged.
The area of ITSs, in particular, uses ideas from the field of artificial intelligence to create teaching environments that provide individualised tutoring. The objective of an ITS is to provide a teaching process that adapts to the student by exploring and understanding the student's particular needs ( Kaplan and Rock 1995). In order to provide this adaptability to the learner an ITS has to be capable of performing diagnosis of the learner's actions to infer the learner's cognitive states, such as his level of knowledge or proficiency. This process of diagnosis is supported by the student model which records these cognitive states of the learner and is constantly updated by (the intelligence of) the system.
The desire to develop ITSs that offer highly individualised tuition is reflected in the strong research focus on the development of comprehensive student models based on the assumption that learners' thinking processes can be modelled, traced and corrected using computers. However, research on complete and precise student models has not shown much progress. Furthermore, the diagnostic processes implemented have remained very domain specific.
Similarly, it has been argued that the student models that have been developed do not provide a guarantee for good remedial tutoring and provision of feedback. It is still unclear what information needs (or can) be formalised in order to provide a basis for the correction of student errors ( Siemer and Angelides 1998).
Another major criticism of ITSs is the fact that student modelling has remained an exclusively cognitive analysis. However, effective tutoring also needs to account for issues such as student motivation and preferences for a particular approach to teaching.
An alternative to the learning theory that treats learning as an individual process can be found within the field of social theory. Within social theory it is argued that cognitive abilities do not result from a simple interaction between the learner and the physical environment, but that such interaction is mediated by others ( Jones 1995). A person's ability to learn is revealed and fostered through interactions with more knowledgeable others ( Crook 1994). Against this background it is claimed that the collaboration of learners also reveals learners'
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