The Vocational Performance Sample (VPS), a vocational assessment instrument for the severely retarded, integrates norm referenced technology with current innovations in domain referenced tests and learning potential assessment. The domains are based on a systematic sampling of types of training procedures and types of discriminations and/or operations currently used in vocational training for the severely handicapped. Correction procedures are integrated into the test format. The test was validated on 158 severely and profoundly retarded adults. Internal consistency was .92; test retest reliability was .92. VPS scores correlated moderately well with both a Supervisor's Checklist Scale and raw scores on the Peabody Picture Vocabulary Test. Criterion related validity was high with VPS scores accounting for over 50% of the variance in training time on a vocational task. (Author)