This study examined the effects of two cognitive styles--field dependents-independents and reflectivity-impulsivity--on learning from microcomputer-based instruction. In the first of three experimental designs, a programmed instruction text on the human heart was used which contained both visual and verbal information in an instructional display, followed by an instructional question and feedback. Subjects were given visual recall tests. In the second experimental design, the same programmed instructional text was used, but verbal recall tests were substituted. The third experimental design was a pilot study designed to evaluate the performance of the subject pool from another experiment on the Barratt's reflectivity and impulsivity cognitive style test. The data from the first two experimental design groups indicated that the line drawing visual type of programmed instruction appeared to have an adequate amount of visual information for learning, and when paired with visual feedback, significantly improved learning. In addition, visual feedback was found to improve learning more than verbal feedback. It was also found that verbal testing alone did not reveal any significant performance differences in the field-dependent-independent group, leading to the observation that testing conditions for intellectual performance must be sensitive to the cognitive style factors being examined. The 180 college freshmen in the third experimental group were found to be more highly cognitively impulsive than impulsive and motor impulsive; these findings will be used in further research on learning from microcomputer-based and programmed instructional materials. The text is supplemented by six tables and four figures. (23 references) (EW)