Carl T. Uhrik
This paper describes several deficiencies of PLANT/ds, an expert system for the diagnosis of soybean diseases. This production system employs both human and machine derived rules. The rule application mechanism for both rule groups suffer from improper treatment of incomplete data. The problem is illustrated by several examples, and a solution is proposed. Implementation of a new version of PLANT on the empty expert system ADVISE is seen as the crux of future research.