AbstractThe study investigated the effects of cognitive mapping on written summarization and comprehension of expository text. Fifty‐one freshmen students participated in the study. The mapping treatment consisted of the development of cognitive maps which graphically illustrated the interrelationships of ideas in expository articles the students read. Following the treatment, students read three expository articles in the Organizational Patterns Test (OPT) with the following rhetorical organizations: enumeration, thesis‐proof, and problem‐solution. The mapping treatment groups scored significantly higher on holistic scores based on written summarizations of thesis‐proof and problem‐solution articles. Mapping treatment students also identified more details, which were used to support main ideas, than did nonmapping students. Moreover, mapping treatment groups used significantly more cohesive ties in writing their summarizations than did the nonmapping group. In addition, mapping students wrote longer and better organized summarizations using the mapping procedure. It was concluded that mapping appears to assist students in developing procedural knowledge resulting in more effective written summarization and in identifyingandusingsupportingdetails in their essays.