Medical diagnosis is an important but complicated task whose automation would be very useful. A scarce resource could be made less so and diagnosis could be made more accurate and efficient in both monetary terms and in reduced suffering or pain for a patient. We have used decision and probability theory to construct such systems from a database of typical cases. This simplifies the task of kno...

ion with equal frequency. Cognitive scientists speak of bask level nodes within a generalization hierarchy whose children share many sensorially recognizable commonalities (Rosch et al. 1976). Other factors that help to characterize a node’s utility compared to those at higher or lower levels of abstraction are concept typicality (bow common are the features of this concept among its sibling co...