It depends. The EEOC, U.S. Supreme Court and Department of Labor have guidelines for deciding if you can use a personality test in hiring. First, it must be validated. Research must show that the test measures what it claims to measure, and that the findings relate to the job. Second, it must compare results to the job’s requirements. Example: “Extroversion” is relevant to sales but not to actuarial work. Finally, it must measure all applicants by the same standard. After deciding sales applicants should be extroverts, for instance, all applicants must be examined by that standard. The Society for Industrial and Organizational Psychology can refer you to qualified testing services in your area; call (419) 353-0032.