ABSTRACT
In recent years, several studies have focused on children's expository writing (e.g., Bereiter & Scardamalia, 1987; Boscolo, 1990, 1991; Cox, Shanahan, & Tinz-mann, 1991; Hidi & McLaren, 1991; Newkirk, 1987; Raphael, Englert, & Kirschner, 1989). Unlike some research that refers to exposition as a broad, nonnarrative genre, this study deals with the type of text whose primary objective is to express information and/or ideas and is well exemplified in school textbooks. This study is particularly concerned with scientific text, that is, text that provides informa-tion on a topic and usually presents a definition of the main object or event (e.g., a plant, an animal, or an atmospheric event), information on its origin or geographic location, a description of its features and/or effects, and classification of subcategories. The comprehension of expository text is by no means a new research field, but the production of this type of text represents a relatively little-explored field, at least from a developmental and educational point of view, although expository writing is a frequent activity in schools.
