While the written word is usually an exceptionally efficient medium of expression, visual media may offer a superior alternative to prose for the communication of some kinds of information. Writers and editors will be best equipped to choose the appropriate medium if their decisions are informed by an understanding of the differences in information processing demands that their choices impose on their readers. The following article examines the kinds of cognitive challenges verbal and visual media present to readers in their efforts to extract meaning from a message.

Part I of this article, pp. 259–272, reviewed the relevant literature on advance organizers and suggested that methodological problems in previous advance organizer studies has not resolved the question of whether advance organizers facilitate the acquisition of subordinate information from text. This question is not an unimportant issue to technical communicators, whose readers often need to acquire factual information as well as more general concepts from the expository text they read. In two studies we investigated the influences of reader's background knowledge, advance organizers, relative importance of idea units, and idea units' position within a text structure on the recall of textual information. Subjects read introductory and text materials and subsequently were tested for their recognition of idea units that were structurally high and important, structurally high and unimportant, structurally low and important, or structurally low and unimportant. In the first study, forty-eight college students were randomly assigned to conditions consisting of relevant or irrelevant background, organizer or no organizer, and text or no text. There were significant main effects for having read a relevant text and for importance of idea units, and an interaction between structural level and importance. A significant organizer by text or no text interaction and absence of a significant main effect for the organizer indicated that the organizer influenced text processing rather than priming relevant prior knowledge, which is a previously undocumented requirement of advance organizer research. In the second study, conducted with eighty-eight college students, we substituted a purpose, no purpose condition for the text, no text condition of the first study. We observed a significant main effect for importance and a significant four-way interaction involving structure, importance, background, and organizer. The more relevant knowledge a reader had, the less dependent he or she was on text structure, and an advance organizer compensated for the absence of relevant prior knowledge.

This article reviews previous research on advance organizers, introductory text adjuncts intended to provide the reader of expository text with a meaningful context within which to process unfamiliar, or difficult, new information. Research conducted during the past thirty years well documents the fact that advance organizers do, indeed, inspire significant increases in comprehension among readers whose prior knowledge “subsumers” are inadequate to provide a necessary assimilative context. One issue on which theorists yet disagree, however, is the efficacy of advance organizers in facilitating the acquisition of subordinate text detail, or facts. Definitional inconsistencies and methodological deficiencies in previous research have clouded this issue. Subsequently in this journal, Part II of this article will present the results of two empirical studies that resolve these methodological problems and specifically address the question of the effects of advance organizers on the acquisition of text detail.