In this study, the effect of a passage organizer (topic sentence) on the ability to identify main ideas was tested. The second purpose of this study was to determine whether main idea comprehension is affected by the type of main idea question asked. Thirty third- and thirty fourth-grade children selected on a random basis from a semi-rural Wisconsin public school were the subjects for this study. The results lend additional support to the theory that passage organization may affect reading comprehension. The implications of this study concerning the effects of passage organization on comprehension are discussed. (RB)