Projective and semiprojective techniques are both tools and tests. A schema for assessing the validity of projective devices is proposed: (1) Primary, consisting of (a) construct validity i.e., the soundness of the techniques vis-a-vis its underlying concepts; and (b) criterion-related validity, i.e., the concordance between tool results and specified external criteria. (2) Secondary, viz., pragmatic validity, i.e., the usefulness of the instrument in applied fields. Discussion then focuses on the construct validity of the conceptually-based, semiprojective Rosenzweig P-F Study. specifically the evidence on (a) the self-consistency of its conceptual dimensions; (b) the sequential. social development of the Types and Directions of Aggression; (c) levels of behavior elicited; (d) sensitivity to scorable changes after induced frustration: and (e) physiological correlates oft he aggression categories. In each of these areas evidence exists in support of the validity of the P-F Study. [ABSTRACT FROM AUTHOR]