This study analyzes the Object Categorization Test (OCT) and the Picture Categorization Test (PCT) to provide (1) psychometric analysis of the tests, (2) substantive analysis detailing variation in performance level as a function of age, race, class, and sex, and (3) normative data yielding frequencies of various score patterns. Data was taken from tests given to more than 500 black and white children from lower and middle class backgrounds. Item analysis revealed that the OCT and PCT were sensitive to sex, education, and test order, and provided a range of types of responses for 4- and 5-year-olds. There were greater differences between ages than within an age group. Test-retest reliability was moderately high. Test order (OCT before PCT, or vice versa) had an effect, interacting with sex and social class of the child. Middle class children tended to provide more consistent response patterns on the OCT and PCT than lower class children, especially lower class black children. Boys and girls showed differential response patterns dependent on test order. Dominant styles of responding to test items were identified for lower class blacks, indicating that styles varied with age, sex, and educational status. Recommendations are made regarding the use of the OCT and PCT. (DR)