Explanatory tools such as simple words, examples, and analogies are ineffective for overcoming an important obstacle to understanding science. This obstacle is that many fundamental scientific principles are counterintuitive (e.g., people resist wearing seat belts partly because scientific notions of inertia are counterintuitive). To assist science writers in presenting science news and concepts, this article identified 1) three major difficulties lay readers often have in understanding science, 2) the kinds of ideas readers find counterintuitive, 3) ineffective approaches for explaining these notions, and 4) effective strategies that help people understand these difficult ideas and their implications for health and safety.

Explaining difficult ideas to lay readers is an important and frequently needed writing skill. When explaining, writers must recognize and overcome the confusions that lay readers may experience in learning abstract concepts. To date, there has been little study of this demanding writing skill. Consequently, this article identifies a particular class of explanatory discourse and proposes working hypotheses about the types of knowledge likely to be associated with skill in this genre. These hypotheses are explored through a study of individual differences in explanatory writing skill among 169 college students. The results of the study showed that variations in the accuracy and adaptiveness of the students' explanations were partially accounted for by measures of topic knowledge, social cognition, and discourse knowledge. A discourse knowledge index and a topic knowledge index were correlated with explanatory writing skill. Cognitive complexity, a measure of social cognition, was associated with adaptiveness in explaining but not accuracy. These findings suggest that explanatory skill is a function of several types of knowledge and that it may be as dependent on discourse or rhetorical knowledge as it is on topical expertise.

This article argues that an understanding of professional and popular science writers' goals provides a basis for both explaining and evaluating their language use. Rhetoricians fault scientists for unnecessarily stilted language; scientists fault popularists for inaccuracy and sensationalism. Although these charges are sometimes justified, they deflect attention from the obstacles writers face and the ways in which they use language to overcome these obstacles.

Explaining difficult concepts to lay readers is an important discursive goal, and yet frequently the quality of explanatory writing is poor. One reason for this poor quality is that the discursive form itself is not well understood. Some studies have identified textual features of effective explanations; however, theoretical characterizations of explanatory discourse are either unnecessarily narrow or overly general. Consequently, this essay offers a new theory of explanatory discourse that is intended to guide analyses of and stimulate improvements in explanations designed for mass audiences. The theory defines explanatory discourse in terms of a particular goal; promoting understanding for lay readers of some phenomenon. This goal is distinguished from those of promoting awareness of new information, proving a claim, or encouraging agreement with a claim. The utility of the theory is demonstrated by showing how it (1) identifies those research literatures most relevant to improving the quality of written explanations, (2) organizes existing findings on explanatory effectiveness in a way that resolves controversies in the literature, and (3) suggests principles for pedagogy pertaining to explanatory writing.

Rubin, Piché, Michlin, and Johnson (1984) recently presented data allegedly demonstrating a substantial relationship between social-cognitive ability and narrative writing skill. Certain theoretical and statistical considerations led us to suspect that the claimed relationship was not actually present in the data reported by Rubin et al. Consequently, two empirical studies were conducted to test for the hypothesized relationship between social-cognitive ability and narrative writing skill, one study reanalyzing data reported by Rubin et al. and the second analyzing original data. The results of the two studies indicate no relationship between social-cognitive ability and rated quality of narrative essays. These findings are discussed in terms of a theoretical model of the relationships among cognitive abilities, discourse aims, and discourse models.