Abstract
Retrieval practice can enhance learning of subsequently studied target information, a phenomenon known as the forward testing effect or test-potentiated new learning. The present study examined whether this effect depends on attentional engagement during encoding. In two experiments, participants studied three lists of unrelated words (Experiment 1) or three educationally relevant prose passages (Experiment 2). After the first two learning blocks, they either restudied the material or were tested on it. Attention during encoding of the final target material was manipulated by a concurrent secondary task. Under full attention, interim testing enhanced recall of the final target material in both experiments and improved performance on a final knowledge transfer test in Experiment 2. Under divided attention, these effects were reduced in Experiment 1 and eliminated in Experiment 2. The findings indicate that the beneficial effect of interim testing depends critically on attention during encoding of the latter studied information.