The effect of categorical presentation on Amer-Ind transparency

Abstract

The study was undertaken to determine whether or not discrepancies among previous studies of Amer-Ind's transparency could be attributed to differences in their method of stimulus presentation. Eighty college students were assigned randomly to one of two stimulus presentation conditions. Subjects in the categorical condition received response forms on which were printed superordinate category labels indicating the types of gestures to be viewed. Subjects in the noncategorical condition viewed the same stimulus gestures, but in random order, and recorded their responses on a form devoid of category labels. Data from 65 subjects naive to Amer-Ind indicated that categorical subjects were only 9% more accurate than noncategorical subjects overall. However, their accuracy was enhanced by as much as 20 to 45% for particular categories of relatively more difficult gestures. The variables of subject age and prior exposure to Amer-Ind also were examined in post hoc analyses. Subject age did not relate consistently to guessing accuracy, although small positive correlations were obtained for several categories of gestures. Data from 14 non-naive subjects indicated that prior exposure to Amer-Ind facilitated guessing accuracy only for subjects in the categorical condition. The implications of these findings for research methodology and clinical application are discussed.