Chairperson, Graduate Committee: Richard BlockShively, Matthew David2013-06-252013-06-252007https://scholarworks.montana.edu/handle/1/2270Spacing and lag effects both refer to abundant findings that memory is enhanced when repeated items are spaced. Several researchers have realized the difficulty of explaining these effects using only one theory, and, therefore posited varying dual-process models. It is also unclear if there is a limit to the increase in memory performance due to increased lag. This study sought to understand how stimulus type influences spacing and lag effects, limits of the lag effect, and the importance of time and items in creating these effects. Experiment 1 found a unique spacing effect and lag effect. Experiment 2 found no spacing effect, yet a lag effect was found. Both time and items are important in generating spacing and lag effects.enMemoryTestingPsychologyThesisCopyright 2007 by Matthew David Shively