Because thematic statements are too global to aid poor readers in comprehending texts, a series of studies using a common procedure was conducted to determine the relationship between teaching thematic concepts prior to reading and reading comprehension. The thematic organizers used in the studies contained three paragraphs that defined the thematic concept of the passage and related this concept to prior knowledge or experiences of the reader. Following the three paragraphs was a set of statements written on the interpretive level. Students indicated whether they agreed with these statements during or after reading. Subjects of the individual studies were elementary, junior high school, and college students. Pretests were used to place students in experimental and comparison groups. Protocols produced by the students were scored according to the degree to which they preserved the meaning of the original textual units. Results indicated that students in the experimental groups recalled more of the most important idea units and presented more complete propositions, the need for the thematic organizer varied according to the learning needs of the students, and poor readers' use of this strategy varied according to interest and the nature of reading disability. (JL)