Offers a definition of explanatory text, and summarizes research on why abstract concepts and principles are difficult for lay readers to understand. Describes a three-week unit for composition classes on spotting difficult ideas, diagnosing the type of difficulty they pose, and selecting the text features most likely to make them less difficult.…

Traces the revision of narrative and expository text made by sixth grade students during a school year in which the focus was on improving reading comprehension and writing through instruction in text structure. Finds that only expository texts were judged to improve in writing quality by year end. (MG)