The knowledge domain defines the knowledge of experts. This knowledge consists of declarative and procedural knowledge.
Declarative knowledge is a set of facts organised to permit reasoning.
Procedural knowledge relates to how a task is performed. It consists of arguments and rules to solve problems. There are two ways of modeling the domain model . A number of criterions are stored in a database, and if the student's input data does not meet the criterion, then he is informed of the performance error. Possible solutions are recommended.