Choosing the right test can be like choosing the right consultant — it requires that you do your homework first.

• Before shopping for a test, figure out what criteria or behaviors are necessary in the job to be filled.
• Look for a test that measures those criteria.
• Assess the tests. You'll need to:
  • know if the test was designed and validated for employment hiring
  • determine whether a test taker can "cheat" on the test
  • see the technical manual describing the research establishing the test's reliability and validity
  • have the test reviewed by your attorney

How do you validate a test? Studying a test to determine whether it actually evaluates what it purports to and whether it is useful as a predictor of job performance is known as "validation." Validation is usually reserved for tests that must be proven not to be discriminatory, i.e., if your business has at least 15 employees or you're covered by state antidiscrimination laws.

There are a number of ways to validate a test.

1. One is to give the test to current employees. Do the best employees have the best scores? If they do, the test may be valid to use on job applicants. This is known as concurrent validation.
2. A second method, predictive validation, is to give the test to applicants but not to use the scores in making hiring decisions. Later, rate these new employees on their job performance. Are the ones who scored highest on the test now doing the best job? If so, the test may be valid to use on applicants in the future.

Do all tests have to be validated? Those tests that screen out a disproportionately high number of minorities, women, or any other protected group must be proven to be a good predictor of job performance.

Moreover, to meet fair employment requirements, each test must be validated for each job.

An industry-wide validation study proving that a test predicts success at welding does not relieve an individual employer who uses that test from its responsibility to validate the test for its own welding positions. Also, a test validated for one location doesn't mean it is automatically validated for other facilities of the same company.

You cannot defend your selection procedures by pointing out that acceptable numbers of minorities and women are being hired and promoted overall. It does not mean that the tests are valid. Since validation can be complicated, you may want to hire a consultant to help you through this process.