1. A method for generating an expert system comprising the steps of: (a) establishing a set of input parameters having input values which define a case situation and establishing a set of output actions in which the relationship between each input parameter and each output action defines a combinatory situation; (b) establishing a decision making structure formed of linked nodes with specified nodes defining questions; (c) generating random values to serve as input values defining a first case situation for a first node; (d) responding by the expert to the questions posed at the first node; (e) generating a new set of random values to serve as new input values defining a new case situation for the first node; (f) repeating steps (d) and (e) until a sufficient number of responses having a predetermined statistical significance is achieved for the first node; (g) generating in turn for each node subsequent to the first node new random values defining a further new case situation biased by a function of a response from a preceding node; (h) responding by the expert to the questions posed at each subsequent node; (i) generating a new set of random values as in step (g); (j) repeating steps (h) and (i) until a sufficient of responses having a predetermined statistical significance is achieved for each of the subsequent nodes.