Too much emphasis in the past has been placed on the appropriate 'type' of validity. That is, researchers typically relied on one of either criterion or content validity to support the uses of a test. This dissertation is a validation study of a police officer entrance examination and follows a construct validation approach which is in line with a unitarian doctrine of validity, using several lines of evidence. Specifically, important predictor and criterion constructs are identified and interrelated in a person-job characteristics matrix. Significant relationships were found supporting the use of the test. Several issues related to validation are discussed as well as the need to develop taxonomic systems to assist in the selection and classification of individuals in an employment setting