The development of a test to measure Locus of Control (IE) in preschool is described. The test is administered individually to a child, who is preferably alone. The set of 40 questions of which the test is comprised posit the occurrence of some reinforcement, and ask the child what the contingencies for the occurrence of the reinforcement are. The child's verbal free response reflects whether he attributes the reinforcement to his own behavior (an internal control response) or to other peoples' behavior or other events (external control responses). The test takes 15 to 20 minutes to administer. A .99 interrater reliability for scoring responses is obtained using a short set of scoring rules. (DB)