The Graduate Course Advisor: A Multi-Phase Rule-Based Expert System
Marco Valtorta, Bruce T. Smith, Donald W. Loveland · 1984
The Graduate Course Advisor (GCA) is a rule-based expert system that advises graduate students in Computer Science. It is implemented in Prolog, using an inference engine modeled after MYCIN's. The advising task is divided into four phases, each of which may apply the inference engine to its own rule base and invoke other procedures. Some phases are diagnostic (e.g., determining a student's needs), whereas others involve planning (e.g., planning a student's schedule). The decomposition helps to manage the complexity of the advising task, it simplifies the knowledge engineering problem, and it will enhance the clarity of explanations. However, the decomposition is tightly bound to basic design decisions; a major decoupling in the GCA followed from our assumption that best schedules are almost always chosen from the top-valued courses.