The Heart Disease Program (HDP)
is a computer program to assist the physician in the
management of patients with complex cardiovascular disorders. The
diagnostic aspect of the management process is the most developed part
of the program and the only part of concern in this paper. The
program's diagnostic reasoning task is to take the findings reported by
the physician and put together a differential consisting of the most
likely hypotheses accounting for the findings. Each hypothesis consists
of a complete causal explanation detailing how the diseases and
mechanisms in the hypothesis provide a consistent accounting for the
findings. The program has gone through two evaluations, one when the
reasoning was based entirely on a probability network[10] and
a more recent evaluation after temporal and severity constraints were
incorporated into the reasoning[11].