In this article, we review research from both experimental and educational psychology that provides strong evidence for the direct effect of testing in promoting learning. After presenting two classic studies, we consider evidence from laboratories of experimental psychologists who have investigated the testing effect. As is the experimentalists' predilection, they have typically used word lists as materials, college students as subjects, and standard laboratory tasks such as free recall and paired-associate learning (see Cooper & Monk, 1976; Richardson, 1985; and Dempster, 1996, 1997, for earlier and somewhat more focused reviews). Effects on later retention are usually quite large and reliable. We next consider studies conducted in more educationally relevant situations. Such studies often use prose passages about science, history, or other topics as the subject matter and investigate the effects of tests more like those found in educational settings (e.g., essay, short-answer, and multiple-choice tests). Once again, we show that testing promotes strong positive effects on long-term retention. We also review studies carried out in actual classrooms using even more complex materials, and they again show positive effects of testing on learning.
