The effect of immediate knowledge of results on test performance was investigated. Three groups of college and high school students used IBM card punchboards to receive immediate feedback after each item of one-half of the items on multiple-choice tests and delayed feedback on the remainder. Two-way analysis of variance was used to test for significant differences in the results under the two conditions on each of ten one-hour examinations and on one final examination. There were no statistically significant differences in means under immediate and under delayed knowledge of results on any one of the one-hour examinations. The difference in results on the final examination, however, was significant beyond the .05 level in favor of immediate knowledge. Immediate item-by-item knowledge of results thus did not depress test performance. The findings appear to justify the recommendation that teachers make greater use of testing devices which give students immediate item-by-item knowledge of test results. (Author/LR)