Validating vocational assessment of severely mentally retarded persons: issues and an application.

The Trainee Performance Sample, an instrument designed to assess vocationally relevant skills of severely mentally retarded persons, employs brief benchwork tasks as content and uses a learning potential (instruction during testing) format. Our investigation of the validity of the Trainee Performance Sample for predicting subsequent training performance provided the opportunity to examine conceptual and methodological issues related to validation of such "learning potential" assessment paradigms. Results demonstrated that Trainee Performance Sample scores appear to be valid, useful predictors of the amount of training necessary for severely retarded individuals to master two prototype vocational tasks.