Fig. 1 Adaptive Intelligent Tutoring System [1]
1.Expert Model: The Expert Model is a computer representation of a domain expert's subject matter knowledge (declarative knowledge) and problem-solving ability (procedural knowledge). This knowledge enables the ITS to compare the learner's actions and selections with those of an expert in order to evaluate what he or she does and does not know.
2.Learner Model: Learner Model is a level of learner’s knowledge while he/she interacts with the tutoring system. The model evaluates each learner's performance from his/her behavior during interacting with the tutoring system in order to determine his or her knowledge, perceptual abilities, and reasoning skills. The model generate evidence and uses inference to provide a number of relevant instructions to individual learner. Instructional Model: Instructional Model contains knowledge for making decisions about instructional tactics. It relies on the diagnostic processes of the learner model for making decisions about what, when and how to present information to a leaner.
3.Interface Model: Interface Model is important for a communication medium and learning environment that can support learner in a task. It can also act as an external representation of the expert model and instructional model.
Adaptive hypermedia and intelligent tutoring system is used for E-learning systems to drive the connection and to personalize instruction on the basis of adaptation to learners learning style. ITS need to be designed and implemented to support modification of lecture content, the decision rules and the fact base of the expert model and the methods to measure performance of learning