The Picture Completion subtest of the Wechsler Preschool and Primary Scale of Intelligence was included in this study as a measure of analytic functioning, an aspect of psychological differentiation. Twelve of the 23 items on the test were taken from the WISC and 11 were new. The child is shown a series of 23 pictures, each of which has some important part missing, and is asked to indicate the missing part. If the child fails to give the correct answer on either of the first two pictures, he is given the correct answer. The test continues through all 23 pictures or until 5 consecutive failures beginning with card 3. Scores were obtained for correct verbal responses, correct nonverbal responses, and total correct responses. The test is reasonably easy to administer, but great care must be taken to question simple labelling responses and to record answers completely. Some children did not understand the meaning of the term "missing" in the instructions. The task was found to be sensitive to age, sex, and SES differences. The test is factorially complex and reflects general competency, a mixture of intellectual competency and cultural experience. Little evidence was found to support its use as a measure of analytic functioning in this group of subjects at this age. (For related documents, see TM 003 174-189, 191-198.) (Author/KM)