Bangert-Drowns, R., Kulik, J., & Morgan, M. (1991). The instructional effect of feedback in test-like events. Review of Educational Research, 61, 213-238.
This meta-analysis of the research on feedback reports on the impact on achievement of the nature of feedback, timing of feedback, and the type of instruction associated with feedback. Among other findings, the authors conclude that feedback does not always increase achievement, immediate feedback and feedback that is more than "correct-incorrect" is associated with larger gains, and feedback is most effective at increasing achievement when students are mindful of the purpose and process of feedback on learing.