Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Richard A. Magill


The relationship between variability of practice and contextual interference was investigated in this study. The hypothesis proposed here was that these two effects are compatible, in that each addresses different learning situations. That is, the contextual interference effect relates only to situations where skill variations are controlled by different generalized motor programs, while practice variability relates only to situations where skill variations are parameter modifications of the same generalized motor program (Magill & Hall, in press). To test this compatibility hypothesis, two experiments were reported that were based on Wulf and Schmidt (1988). Blocked and random practice schedules were added to their design, resulting in a 2 by 2 (same vs different relative timing) experimental design. A variety of retention and transfer tests were used to investigate the specific conditions that favor the demonstration of practice schedule effects. A control group which received no acquisition training, was added in Experiment 2. Results from both experiments showed the typical contextual interference effect with depressed scores by the random groups during acquisition and superior scores on both transfer and retention tests. Certain characteristics of the transfer and retention tests were found to influence the demonstration of the practice schedule effects. Results supported the hypothesis that the variability of practice prediction and the contextual interference effect are compatible. In a multiple skill practice setting, practice schedule may or may not influence learning, depending on the characteristics of the skills being learned. If skill variations are from different classes of movements, then learning benefits due to high interference practice schedules will occur. However, if the skill variations are from the same class of movements, practice schedule benefits will not occur.