Choice Reaction-Time as a Function of Meaningful Similarity
Norman J. Slamecka · The American Journal of Psychology · 1963
The time required to make a choice between alternative stimuli has been shown to be directly related to the degree of physical similarity between the stimuli. Several studies exemplifying this relationship have used displays varying along such physical continua as wave-length, frequency, and linear extent.' All these types of stimuli allow for an independent, objective measurement of the distances between the alternatives. Non-sensory or psychological continua have not, however, been given the close attention that they merit, and we stress particularly the attribute of similarity of word-meaning. Considering the salient role of words as discriminative stimuli governing human behavior, it is surprising that there is but one published report of the effects of the similarity of meaningful words upon latencies of responce.2 In Dember's study, S was required to choose between two pairs of words, the one pair whose members appeared closer together in meaning. A pool of five words was used, from which pairs were formed, (viz. always, often, rarely, seldom, and never), and data were obtained from a single S. A significant negative relationship was found between reactiontime and perceived distance between the word-pairs. In spite of the elegance of demonstrating the relationship with an N of one, it seemed to us desirable to conduct a more extensive investigation of this problem, using both more Ss and a wider range of stimulus-words, in order to extend the generality of the findings. Also, rather than asking S to choose between two pairs of words (a requirement in the Dember study, dictated by the use of the Method of Cartwheels), we decided to require a choice between two single words. Finally, since the concept of meaningful similarity is certainly not an unambiguous one, it seemed appropriate to break it down into the sub-aspects of denotative similarity (definition) and connotative similarity (properties and associations). In each of the three experiments to be described, it was hypothesized that choice reaction-time for a pair of words would be positively related