The purpose of this study was to determine whether different types of practice strategies are equally effective in facilitating encoding strategies and in subsequent information acquisition and retrieval by students identified as possessing high, medium, and low prior knowledge levels in a content area. Within the context of the encoding-specificity principle, the effectiveness of verbal and visual testing of information acquired from visually complemented instruction was also investigated. Subjects, who were 240 graduate and undergraduate students, were randomly assigned to eight treatment groups which determined the level of practice received and the testing mode (verbal or visual). Each student received a pretest, participated in the instructional presentation, and then received a battery of tests designed to measure various educational objectives. Results indicated that practice strategies: (1) can be effective instructional variables in improving student achievement; (2) function differentially in promoting student achievement of different educational objectives; and (3) can function to reduce differences among students possessing different levels of prior knowledge. Additionally, it was found that visual tests appear to be more effective than verbal tests in assessing information communicated by visualized instruction. Supplemental materials include sample test questions, statistical data, and 54 references. (MES)