College of Liberal Arts

For more than a century, measurement experts have distinguished between time-limited tests and untimed power tests, which are administered without time limits or with time limits so generous that all students are assured of completing all items. On untimed power tests, students can differ in their propensity to correctly respond to every item, and items should differ in how many correct responses they elicit. However, differences among students' speed of responding do not confound untimed power tests; therefore, untimed power tests ensure more accurate assessment. In this article, we present four empirically based reasons to administer untimed power tests rather than time-limited tests in educational settings. (1) Time-limited tests are less valid; students' test-taking pace is not a valid reflection of their knowledge and mastery. (2) Time-limited tests are less reliable; estimates of time-limited tests' reliability are artificially inflated due to artifactual consistency in students' rate of work rather than authentic consistency in students' level of knowledge. (3) Time-limited tests are less inclusive; time-limited tests exclude students with documented disabilities who, because they are legally allowed additional test-taking time, are often literally excluded from test-taking classrooms. (4) Time-limited tests are less equitable; in addition to excluding students with documented disabilities, time-limited tests can also impede students who are learning English, students from underrepresented backgrounds, students who are older than average, and students with disabilities who encounter barriers (e.g., stigma and financial expense) in obtaining disability documentation and legally mandated accommodations. We conclude by offering recommendations for avoiding time-limited testing in higher educational assessment.