Commentary: The Interaction between Knowledge and Structure Variables in the Processing of Expository Prose

Abstract

THE AUTHOR argues that previous research on text processing has led to inconsistent findings because researchers have generally focused on the influence of either the world knowledge that the reader brings to the text or the structure of the text itself, but have ignored the interaction between the two. Although the statistical principles of this interaction are well understood, its practical significance is not sufficiently appreciated. The author reviews the research on the effects of world knowledge and text structure variables on comprehension and concludes that text structure is most important when the subject matter is moderately unfamiliar to the reader, because the reader can use knowledge of the structure to construct the relations between the concepts in the text. In contrast, if the text is on a familiar topic, then the relations between concepts are already known, and if the text is quite difficult, the reader cannot discover the relations in the text even using the structure. Although structure variables are important only for moderately unfamiliar material, it is from such text that readers most often acquire new knowledge. The author uses this interpretation of the interaction between structure and knowledge to explain many of the conflicting findings in previous research, and suggests that future studies should manipulate knowledge and structure variables simultaneously, in addition to other variables of interest.