This study examined the effect of distributed questioning on learning and retention in a college lecture course. A total of 48 question pairs were presented over four exams. The 16 question pairs associated with each of the three blocks of the course appeared on the block exams, and all 48 appeared on the final exam. The two questions in each pair were related to each other, so that knowing the answer to one question usually implied knowing the answer to the other. One question in each pair was included in an experimental condition, in which questions were presented online, in class, or both online and in class, before appearing in exams. These conditions were counter-balanced across the sample. The control questions appeared only in exams. Providing a question online in advance of class, as well as in class, had a significant long-term effect on the probability of knowing the answers to both experimental and control questions when they appeared in exams. These results demonstrate that coordinated online and in-class instruction can significantly improve exam performance. These results are consistent with the hypothesis that distributed instruction creates more robust memory traces, rather than the hypothesis that it creates additional memory traces. (Contains 1 table and 5 figures.)