The lag effect and differential organization theory: nine failures to replicate

In our first experiment, we tried to replicate and extend previous results that had provided seemingly convincing support for a differential organization explanation of the monotonically increasing lag effect in free recall. However, we failed to obtain the lag effect. Eight additional experiments also failed to replicate the lag effect. In all, we made 918 observations of performance on items repeated at each of three lags, and the mean percentage of correct free recall varied by less than one percentage point. These results suggest that there are boundary conditions limiting the generality of the monotonically increasing lag effect in free recall. In addition, caution should be exercised in accepting certain previous findings as strong evidence for a differential organization explanation of the phenomenon.