Few attempts have been made to establish the same-different judgment task as a means of identifying separable versus integral dimensions. Most were not motivated by a precise theory of dimensional interaction and thus suffered from a number of potential confounds. Ashby, Townsend, and colleagues have developed an important model of the psychophysical identification task, termed General Recognition Theory (also call Decision Bound Theory) that is based on multidimensional signal detection theory. This theory provides the ability to assess the nature of the perceptual representations of stimuli (e.g., their dimensional interactions), within a single framework and across paradigms. The theory has been extended to categorization, Garner filtering, similarity judgments, and preference successfully. This paper reports an empirical application of an extension of the theory to the task of same/different judgments as a means of investigating dimensional separability. Data obtained from same-different judgments using stimuli composed of traditionally separable dimensions generally provide support for the validity of this task as a means of understanding dimensional interactions in contrast to previous findings.