Verbal Responses and Concept Formation
In a series of studies Heidbreder ( 2 ) has tried to determine the relative difficulty and speed of attainment of concepts. The increasing order of difficulty is from concrete objects, to form, to numbers. Dattman and Israel (1) modified the Heidbreder pictures and found no differences in difficulty, contrary to Heidbreder's explanation. Inspection of their modified stimuli, however, suggests that their changes merely altered the original response probability. In the present study 200 col1e;;e Ss were shown large copies of the Heidbreder pictures with instruction to write :he first response suggested by each picture. There were 15 stimuli assigned to each of the three concept classes. Each response was classified as to response concept class. For example, for a picture of 6 V-shaped lines, "Birds" was classified as an object response, "V's" as a form response, and "six" as a number response. If the most probab!e response to a stimulus corresponds to the assigned concept class to be learned in a paired-associate presentatian, faci!itation should occur. If the most probable response competes with the concept class to be learned, there should be interference. In all stimulus categories the most probable response was object name rather than form or number. Mean number of responses falling into each response concept class was: object, 38.50; form, 4.05; number, .40; unclassified, 2.32. Of the 15 pictures to which a nonsense syllable was learned on the basis of the object name by Heidbreder's Ss, 14 m7ere responded to wirh cbject names. 15 form stimuli elicited 1.75 form responses. IS numbz szimuli elicited .34 number responses. 15 less the number of responses indicates the number of competing responses presumed to interfere with acquisition of correcl: responses. The decrease in frequency of agreemzne of stimulus and res2onse concept classes from object, to form, to number is consistent with the decreasing ease of role concept learning ( 2 ) . The digerences are due to previously learned verbal habits in terms of the most probabie response and strengths of competing responses to each stimulus.