The effects of prereading techniques, specifically "advance organizers" and "structured overview" were studied by comparing retention and comprehension of reading material in high school students with and without prereading treatment. An advance organizer is a brief passage giving a general and inclusive introduction to material to be read. A structured overview consists of student-teacher interaction dealing with terms and concepts related to the material to be read. The subjects were 157 students in social studies classes in a rural Virginia high school. Subjects were tested on reading ability and classified in four reading ability groups. Subjects were then divided into three treatment groups: one group received the advance organizer, one a structured overview, and the control group received no prereading treatment. Students were given a 3,000-word passage on labor unions (an unfamiliar topic), and 24 hours later they took a 22-item test on the passage. Results showed no statistically significant differences between the three groups, although the structured overview group performed consistently better than the advance organizer group. When reading ability was high or low, the control group was lower or equal to the experimental groups, but when reading level was commensurate with that of the passage, the scores of the control group were higher. Tables and references are included. (AL)