Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Richard A. Magill


While previous studies attribute the superior learning associated with random practice to cognitive-mediated factors (i.e., Shea & Zimny, 1983; Lee & Magill, 1985), the extrinsic characteristics of the task and how subjects respond to them have not been considered. One view is that blocked and random practice conditions impose differential constraints on performance (Newell & McDonald, 1992). The two experiments reported here sought to test this view, with the assumption that differences in search strategies would be identified at the level of kinematic performance. In Experiment 1, a quantitative analysis of kinematic variability was used to assess the contextual interference effect. The task involved tapping a series of disks in a particular pattern with a hand-held stylus. These movements were recorded and analyzed using the Peak Performance Motion Analysis System. Subjects (28 females) were randomly assigned to blocked or random practice conditions. A double-transfer design resulted in four practice-retrieval conditions. Subjects received 36 practice trials on each of three different movement patterns during acquisition, followed by a 10-minute retention interval. Three trials of the practiced patterns and three trials of a novel pattern were performed during retention and transfer testing. Analysis of kinematic performance revealed that the practice schedule manipulation led to differences in kinematic variability, with random practice and random retrieval conditions resulting in greater kinematic variability than blocked practice and blocked retrieval conditions. Experiment 2 extended this finding by introducing an extrinsic source of kinematic variability into blocked practice performance. Subjects were required to strike different regions of the disk while performing a movement pattern. This extrinsic variability was expected to lead to improved learning under blocked practice conditions because it encouraged a wider search of the perceptual-motor workspace. Analysis revealed an increase in kinematic variability during acquisition for blocked practice subjects in the variable target condition, with this variability leading to improved retention and transfer performance. These findings are discussed in relation to cognitive-based interpretations of the contextual interference effect.