Approaches to probabilistic unfolding

The method of paired comparisons is a technique for the collection of data used in a variety of fields such as acoustics, animal ecology, choice behavior, dentistry, economics, epidemiology, food science, marketing, optics, personnel testing, preference testing, psychometrics, sensory testing, sports, taste testing and others (David, 1988). Alternatives are presented in pairs to one or more subjects, who are asked to pick one of them. Making such a binary choice is probably the simplest of all choice tasks. For this reason, this method is primarily used in cases where judgements are necessarily subjective. The method is essentially due to Fechner, and several parametric and nonparametric methods for analyzing such data have been proposed ever since. Bradley (1976) and David (1988) have summarized most of these methodological approaches.