| Abstract: | For a certification, licensure, or placement exam, allowing examinees to take multiple attempts at the test could effectively change the pass rate. Change in the pass rate can occur without any change in the underlying latent trait, and can be an artifact of multiple attempts and imperfect reliability of the test. By deriving formulae to compute the pass rate under two definitions, this article provides tools for testing practitioners to compute and evaluate the change in the expected pass rate when a certain (maximum) number of attempts are allowed without any change in the latent trait. This article also includes a simulation study that considers change in ability and differential motivation of examinees to retake the test. Results indicate that the general trend shown by the analytical results is maintained—that is, the marginal expected pass rate increases with more attempts when the testing volume is defined as the total number of test takers, and decreases with more attempts when the testing volume is defined as the total number of test attempts. |
