PROSPECTOR was an expert system developed at Stanford in the
late 1970s to evaluate geological sites for potential mineral deposits. In 1984 it was
instrumental in discovering a molybdenum deposit worth 100 million dollars.
PROSPECTOR was based on a semantic network and used a combination of mostly forward chaining and some backward chaining. It adopted a form of depth first search guided by the probabilities of different hypotheses and used Bayes Theorem to deal with uncertainty. The dialogue component and explanation component used mixed control.