Testing Improves Performance as Well as Assesses Learning: A Review of the Testing Effect With Implications for Models of Learning

Taking a test of previously studied material has been shown to improve long-term subsequent test performance in a large variety of well controlled experiments with both human and nonhuman subjects. This phenomenon is called the testing effect. The promise that this benefit has for the field of education has biased research efforts to focus on applied instances of the testing effect relative to efforts to provide detailed accounts of the effect. Moreover, the phenomenon and its theoretical implications have gone largely unacknowledged in the basic associative learning literature, which historically and currently focuses primarily on the role of information processing at the time of acquisition while ignoring the role of processing at the time of testing. Learning is still widely considered to be something that happens during initial training, prior to testing, and tests are viewed as merely assessments of learning. However, the additional processing that occurs during testing has been shown to be relevant for future performance. The present review offers an introduction to the historical development, application, and modern issues regarding the role of testing as a learning opportunity (i.e., the testing effect). We conclude that the testing effect is seen to be sufficiently robust across tasks and parameters to serve as a compelling challenge for theories of learning to address. Our hope is that this review will inspire new research, particularly with nonhuman subjects, aimed at identifying the basic underlying mechanisms which are engaged during retrieval processes and will fuel new thinking about the learning-performance distinction.