Testing improves true recall and protects against the build-up of proactive interference without increasing false recall.

Retrieval practice has been shown to protect against the negative effects of previously learned information on the learning of subsequent information, while increasing retention of new information. We report three experiments investigating the impact of retrieval practice on false recall in a multiple list paradigm. In three different experimental designs participants studied blocks of interrelated words that converged on non-presented associates. Participants were tested either after every study block or only after the fifth study block, and both groups received a cumulative test on all five study blocks. Overall the results from all three different experimental designs point to a benefit of testing in increasing long-term veridical recall on the cumulative test. More importantly, this improvement in veridical recall did not come at a cost: False recall on the cumulative test did not increase from retrieval practice.