A Factor Analytic Study of Stimulus Values of the Thematic Apperception Test

Schmitz, Thomas J. (Ph.D., 1965)

Thesis directed by Assistant Professor Peter G. Ossorio

Projective techniques are widely used by clinical psychologists, yet there are many unanswered questions regarding what determines the response to an inkblot or to an ambiguous picture such as Thematic Apperception Test cards. Present formulations of an individual's responses to projective tests emphasize an interaction between factors such as the person, the stimulus and the examiner. The TAT, even though it is the third or fourth most widely used test, has rarely been studied in terms of the present formulations regarding test responses. In particular there have been no extensive investigations of the stimulus values of the Thematic Apperception Test materials.

A linguistic judgmental method was employed in the present study of the stimulus values of Thematic Apperception Test cards. A wide variety of verbal expressions were used to define a series of ten point scales on which TAT cards and verbal expressions of Murray's Needs and Press could be rated. The data were factor analyzed at Western Data Processing Center using Comrey's minimum residual method of extraction and a varimax rotation procedure.

In the major analysis 112 variables consisting of verbal expressions of Murray's Needs and Press, together with other scales used in earlier semantic studies were factor analyzed. Subsequently ratings of 42 TAT and "control" pictures with respect to these 112 variables were used to compute the coordinates of these pictures within the stimulus value space provided by the factor analysis. The results of the factor analysis are consistent with previous semantic studies, and the results of the factor measurement procedure, i.e., the characterization of the TAT cards by means of their stimulus value coordinates is consistent with clinical evidence and previous experimental evidence as to the "pull" of each card. The use of stimulus value coordinates provides a flexible, objective basis for the selection of TAT cards in a given clinical application. An examination of the coordinate values of the various cards indicates reasons why some cards are more clinically productive than others.

A second set of factor analyses was performed on Male, Female and Combined ratings of 42 TAT and "control" pictures together with 76 verbal expressions of Need and Press. These 118 "object concepts" were rated on a series of 76 scales defined by Murray's Needs and Press and on 36 scales used in earlier semantic studies. These three factor analyses, Male, Female, and Combined ratings, each extracted from 15 to 39 factors. In every instance there were two factors extracted which together accounted for approximately half of the total variance. One of these two large factors in each analysis was a factor composed primarily of verbal expressions of Murray's Press, while the second large factor was made up of TAT cards and expressions of Murray's Needs. These results were interpreted as consistent with Murray's conceptualizations of Need and Press as different but general theoretical concepts. [214 pp.]