A Simplified Version of the Method of Transitions

Abstract

This paper proposes a simplification of the method of transitions, which is used for the determination of the individual points of subjective equality from data obtained by the methods of constant stimuli or of paired comparisons. It is suggested that the estimated probabilities of transitions should no longer be computed from the psychometric function derived from the normal distribution function that fits the obtained frequency distribution of transitions, instead they should be computed directly from the psychometric function that fits the obtained proportions of response. This new procedure makes the use of a previous cumbersome fitting algorithm unnecessary Experimental tests show that the simplified version of the method causes no substantial loss in information when the standard falls within the range of variable stimuli.