Failures to replicate hyper-retrieval-induced forgetting in arithmetic memory.

Campbell and Phenix (2009) observed retrieval-induced forgetting (slower response time) for simple addition facts (e.g., 3 + 4) immediately following 40 retrieval-practice blocks of their multiplication counterparts (3 × 4 = ?). A subsequent single retrieval of the previously unpracticed multiplication problems, however, produced an retrieval-induced forgetting (RIF) effect about twice as large for their addition counterparts. Thus, a single retrieval of a multiplication fact appeared to produce much larger RIF of the addition counterpart than did many multiplication retrieval-practice trials. In several subsequent similar studies, however, we failed to observe this hyper-RIF effect. Here, we attempted an exact replication of the Campbell and Phenix experiment, but found no evidence of hyper-RIF. We conclude that the hyper-RIF effect reported by Campbell and Phenix is an elusive phenomenon; consequently, it cannot at this time be considered an important result in the RIF literature.