The multiple dual-pair method

A model for the multiple dual-pair method, a generalization of the traditional dual-pair (4IAX) paradigm, is given. This model is expressed in terms of normal and beta distributions. This generalization allows for the simultaneous estimation of the perceptual distances among three or more stimuli. This model has applications in cases in which multiple two-sample comparisons would be too time consuming and labor intensive. The theory discussed shows how unequal variances can be estimated on the basis of results from that method. Two numerical examples that illustrate the ability of the beta distribution-based model to retrieve the appropriate parameters are given. It is also shown how the traditional dual-pair model is a special case of the multiple dual-pair model.