The distinction between aptitude and achievement tests is more a matter of use than content (Gregory, 1994a). In fact, any test can be an aptitude test to the extent that it helps predict future performance. Likewise, any test can be an achievement test insofar as it reflects how much the subject has learned. In practice, then, the distinction between these two kinds of instruments is determined by their respective uses. On occasion, one instrument may serve both purposes, acting as an aptitude test to forecast future performance and an achievement test to monitor past learning