The ratio theory of intermediate size discrimination.

Abstract

A theory based on Kelson's adaptation level formulation was presented that was capable of integrating the data on the problem of transposition of intermediate size. These data were analyzed and new research reported that revealed several phenomena of importance for any theory of intermediate size discrimination. The modes of response either replicated or reported were transposition, systematic preference for the absolute stimulus, neither absolute nor relational choice, equal preference for 1 test stimuli, and random response. The ratio theory was able to deal with the experimental results and to predict the points of transition from one mode of response to another. The limitations and the implications of the theory were discussed. THE INTERMEDIATE SIZE PROBLEMTransposition has been a central concern for theories designed to explain the essential nature of the stimulus in discrimination learning. However, evidence opposed to all theories that have attempted to account for transposition has been revealed by research on the intermediate size problem. The first study that employed three stimuli differing in size and simultaneously presented was that of Spence (1942) which showed that response in test was predominantly to the specific stimulus on which the subjects (chimpanzees) had originally been trained. Spence considered these data to be strong evidence against both a relational (Kohler, 1955) and a configurational (Gulliksen & Wolfle, 1938) theory and extended his earlier formulation (Spence, 1937) to account for the intermediate size 1 This paper is based on a dissertation submitted to the Graduate Faculty of the New School for Social Research in partial fulfill ment of the requirements for the PhD degree. The writer wishes to express his gratitude to the chairman of his dissertation committee, Jerome Wodinsky, for his interest and invaluable advice during all stages of the development of this study.1 Now at Wellesley College.

SOLUTION OF THE INTERMEDIATE SIZE PROBLEM BY PIGEONS1

“…A recent review of the literature (Zeiler, 1963) revealed that species other than pigeons transposed when the training and the test sets were similar to each other. With the extinction series, the current findings were that pigeons transferred absolutely whether or not the training and the test sets were very similar.…”

“…The assumption is that stimulus preference in the test is controlled by the nature of the effective stimulus in the original discrimination. This may be the middle-size relationship, the absolute physical size of the SD, or some contextually determined property (Zeiler, 1963). Since the stimulus responded to in the test would differ depending on which of these properties controlled the discriminative behavior, the essential nature of the stimulus is identified by the test element chosen.…”

The dependency of intermediate size problem responses upon sets in human Ss

“…(For theoretical analyses, see Goldstein, Krantz, & Rains, 1965;Spence, 1942;Zeiler, 1963aZeiler, , 1963bZeiler, , 1964.) Each of these theories assumes (a) Ss are alike with respect to the stimulus property used as a cue, and (b) no S has more than one basis for responding; but these assumptions appear doubtful for human Ss.…”

The effect of two training sets on transposition in adults

“…While young children transpose with test sets one step removed from the training set and show first absolute and then random response as the test inc reases in distance from the training set (Zeiler, 1963) and somewhat older children display relational transfer at all distances (Kuenne, 1946), a recent study with adults (Zeiler, 1964) revealed quite different effects.…”