Report Number: CS-TR-85-1067
Institution: Stanford University, Department of Computer Science
Title: Acquiring, representing, and evaluating a competence model of
Author: Clancey, William J.
Date: August 1985
Abstract: NEOMYCIN is a computer program that models one physician's
diagnostic reasoning within a limited area of medicine.
NEOMYCIN's diagnostic procedure is represented in a
well-structured way, separately from the domain knowledge it
operates upon. We are testing the hypothesis that such a
procedure can be used to simulate both expert problem-solving
behavior and a good teacher's explanations of reasoning.
The model is acquired by protocol analysis, using a framework
that separates an expert's causal explanations of evidence
from his descriptions of knowledge relations and strategies.
The model is represented by a procedural network of goals and
rules that are stated in terms of the effect the problem
solver is trying to have on his evolving model of the world.
The model is evaluated for sufficiency by testing it in
different settings requiring expertise, such as providing
advice and teaching. The model is evaluated for plausibility
by arguing that the constraints implicit in the diagnostic
procedure are imposed by the task domain and human
This paper discusses NEOMYCIN's diagnostic procedure in
detail, viewing it as a memory aid, as a set of operators, as
proceduralized constraints, and as a grammar. This study
provides new perspectives on the nature of "knowledge
compilation" and how an expert-teacher's explanations relate
to a working program.