ABSTRACT
A graduate student in a social science discipline seeks help from an advisor about developing a sampling strategy. The interaction develops in a time-honoured way. The advisor asks questions about the purpose of the study, the population from which the sample is to be drawn, the likely analytic procedures and so on. The student supplies answers to the questions, clarifies points, makes decisions. Finally, a recommendation about an appropriate sampling procedure is made. Interactions like this are common enough. The difference in the consultation just described is that the advisor is not a human but a computer program — an expert system. Expert systems — a branch of artificial intelligence, a computer science specialism that seeks to emulate human cognitive processes — encapsulate the knowledge held by an expert in a precisely defined field or domain, and, in consequence, are sometimes called knowledge based systems. In the vignette above the expert knowledge encapsulated in the expert system is that of a statistician.
