DR MECHO : a deep reasoning approach to subject knowledge in ICAI.
Knowledge bases require a considerable investment of time and
money to construct. For many applications the dual use of a knowledge
base in an expert system and in a teaching system would be cost effective.
This research addresses the issue of whether a single knowledge
base that can be used effectively in an expert system can form the
basis of a functionally effective teaching system.
To understand what is meant by a "functionally effective" teaching
system a review of computer-aided instruction and intelligent
computer-aided instruction systems has been carried out. From this, a
list of twelve functional requirements were identified that should be
met by the subject knowledge contained in a teaching system, and therefore
by a dual-purpose knowledge base.
A review of expert systems was also undertaken, and this resulted
in the generation of the hypothesis that the deep knowledge approach to
the construction of expert systems could be used for the construction
of a dual-purpose knowledge base.
A test system, DR MECHO, was constructed from the MECHO program,
which solves problems in the domain of statics. This new system
included: a deep knowledge base; a meta-interpreter, to provide explanations
of the reasoning process of DR MECHO; and a set of actions,
referred to as teaching actions, which could replace some of DR MECHO's
usual problem solving operations with student input.
The performance of DR MECHO as an expert system, and its ability
to meet the functional teaching requirements, were evaluated. DR MECHO
performed well as an expert system. It also met most of the teaching
requirements. The main underlying reasons for the latter were: its performance
as an expert system, the explicit structuring of the knowledge
base, and the observance of the "no function in structure" principle
(the latter two being characteristics of deep knowledge systems