This report covers a series of learning experiments utilizing lists of paired- associates (word pairs). Each experiment consists of three phases. In the first phase the subjects learn a list of paired-associates to a certain performance level. In the second phase (interpolated learning) other sets of paired-associates are learned. Finally, phase three consists of recall of the list from the first learning phase. Here the experimenters were interested in how different kinds of interpolated learning affect recall. The first experiment varied the incentives offered during the interpolated phase. It was found that learning the interpolated list did interfere with recall of the first list (retroactive inhibition); however, the amount of interferences did not vary as a function of the size of the incentive. The second experiment explored the effect of different incentives and different instructions about how to learn the work lists. Regardless of the type of instructions, more of the low-pay-off, interfered-with terms than high-pay-off, interfered-with terms from the original list were recalled. The third experiment increased the amount of interpolated learning to be done. In this case, a pay-off for learning interfering, interpolated items produced less interference for males than females. (LR)