4/102.3.1.2 Student model
The student model defines the student's knowledge dynamically at every stage of the program. The student's knowledge also consists of both declarative and procedural knowledge. In the ``overlay model'' the student's knowledge is treated as a subset of the expert's knowledge. Learned parts of the knowledge are just marked in the expert model.In the ``buggy model'' or ``deviation model'' the difference between the student's performance and the expert's performance is determined. The student's answers are analysed and the deviation from the expert's knowledge is determined. The database consists of missing conceptions and misconceptions. A missing conception is an item of knowledge that the expert has but the student lacks. A misconception is an item of knowledge that the student has but the expert does not.