A study of first-year college students (n=121) in Taiwan investigated the effects of navigation maps and learner cognitive styles on performance in searches for information, estimation of course scope, and the development of cognitive maps within a hypertext learning course. Students were tested to determine level of perceptual field dependence and assigned to one of five groups: no map, global map, local map, local tracking map, and all maps. Students searched particular sections, and browsed through the course "Introduction to Computer Networks" delivered by the Cooperative Remotely Accessible Learning (CORAL) system, a courseware browser. Navigation map type has significant effects on students' search steps, search efficiency, and development of cognitive maps. Subjects in the global map and all-map groups took fewer steps and had higher search efficiency than subjects in the other groups. Map type also contributed to a significant difference in cognitive map development scores, with all-map and global map groups scoring higher than other map groups. Map type did not cause a significant effect on either search-task completeness or estimation accuracy. Cognitive style had a significant effect on subjects' cognitive map development, but did not have a significant effect on subjects' search performance. (Contains 24 references.) (Author/SWC)