The Discourse Matrix
Ellen W. Nold, Brent E. Davis · College Composition and Communication · 1980
that every paragraph has a topic sentence, and that any subsequent sentence is either coordinate or subordinate to the one directly before it. As Karrfalt2 notes, however, there is a major problem with Christensen's analysis in that sentences are frequently neither coordinate nor subordinate to the preceding sentence, but superordinate to it. Although D'Angelo3 does not seem to recognize this problem, he does propose an interesting extension of Christensen's theory of generative rhetoric to the essay. Actually, we feel that all three men have hit upon key pieces in the puzzle of devising a psychologically accurate and pedagogically useful representation of the structure of texts; such a representation is necessary for both theoreticians and instructors who wish to account for and describe both the way a writer writes such texts and the way a reader makes sense of them. In this paper we propose a model of text structure that seems to be not only more psychologically accurate than others, but also more pedagogically useful. A number of models seem to be at least to some degree psychologically accurate. Cognitive psychologists have recently tested the validity of such models by determining how accurately they predict a reader's difficulty in reading texts. Two psychologists, Kintsch and Vipond,4 suggest that readability is inversely proportional to the load the text places on short term memory. In their experiments they invite subjects to divide texts into segments and then ask them to compose sentences expressing the gist of each segment on whose boundaries half or more subjects agree. In an analysis too complex to describe here, Kintsch and Vipond determine the semantic interrelationships between the gist sentences, usicg the system exemplified in Kintsch's other work.5 Though this system appears to be able to predict readability of a text more accurately than other readability formulas, it is much too cumbersome for pedagogy.