To evaluate the use of semantic organizers as a means of improving the prewriting techniques of composition students, a study was made of two separate groups of college freshman composition students during an intensive, five-week writing workshop. Data were also collected from case studies of students in the experimental group, including frequent interviews and informal discussions. The experimental group was taught the use of semantic organizers as part of their prewriting process. This involved teaching them how to organize their brainstorming of a topic around a key word or nucleus phrase, allowing for the flowing of concepts from that key word. The control group was taught to use more conventional prewriting approaches, particularly modeling and outlining procedures. The instruments for comparative evaluation were students' written responses to three letters from their instructors on identical topics at three points during the course--the beginning, middle, and end. The comparison of results from the three test themes showed surprisingly strong general progress for the experimental group using semantic organizers, while the progress of the control group was slightly better than what had been anticipated for the test group as a whole. Results also seemed to suggest that the use of semantic organizers improved student attitudes and increased motivation. (HOD)