This paper aims at quality improvement of a programming exercise course, and proposes a framework for the exercise assist system with the following features:(1) an exercise system, with a description of the structural algorithm as its core; (2) the assist service, utilizing the teacher and operational knowledge; (3) the assist environment adapted to the percentages of students with varous degrees of progress. Then, defining the pair consisting of the student number and the task number as the unit in the exercise assist operation, it is shown that the relation between the state of the student and the assist service can be interpreted by the blackboard model.
A reasonable realization of the forementioned model is discussed, considering both the service response and the effective use of the resources such as the processor and the memory. A construction scheme is proposed, based on the hierarchical blackboard. A prototype system is constructed based on the proposed concept. By a benchmark test, the relation between the response time of the assist service and the implementation memory capacity of the workstation is shown, and the superiority of the hierarchical structure over the nonhierarchical structure is quantitatively demonstrated. As an item of the performance evaluation, an experiment is used to analyze the relation between the system response time and the psychological satisfaction of the user. The threshold for descriminating satisfaction and dissatisfaction of the user is determined. © 1997 Scripta Technica, Inc. Syst Comp Jpn, 28 (1): 34–45, 1997