Three studies were conducted to investigate the development of the ability of individuals of varying ages to use macrorules for paraphrasing expository text. Macrorules were defined as the general rules of deletion, superordination, selection, and invention that underlie comprehension of prose. In the first study, 18 fifth grade, 16 seventh grade, 13 tenth grade, and 20 college students were given expository texts and told to summarize them. They were allowed to do anything that would help them write good summaries, including taking notes, underlining text, writing rough drafts, and keeping their notes and rough drafts at hand while summarizing. The results were marked for use of macrorules by independent raters. In the second study, college rhetoric instructors ("experts") completed a similar task. In addition to summarizing the material, they were asked to talk about their methods for completing the task and about how they taught their students to summarize. In the third study, 20 junior college students ("novices"), completed a similar task. Results showed that older high school students, college students, and "experts" wrote better and used rules more efficiently while writing than did younger students and novice writers. There was also a marked tendency on the part of more mature students to rearrange material across paragraphs, combining according to common topic. (FL)