The Function of Non-verbal Elements in Scientific Discourse

Abstract

When reading a biology or chemistry textbook one of the saliente characteristics one might notice; is the great amount of visuals contain in them. These visuals usually take the form of charts; diagrams; drawings; photographs; graphs or tables to complements or illustrate the written text. Such visual componentes have generally been considered merely as "illustrations" which the writer uses in order to exemplify his message. However; illustration is not their only function. It is the purpose of this paper to show that non-verbal elements in written scientific discourse should not be considered simply as illustrations that bring "life" to the text; but as components of discourse which fulfill different communicative functions; this paper does not report results of a text analyys to determine the frequency of occurrences of certain formal features of scientific language in writtten discourse. It reports the results of a discourse analysis aimed at revealing the communicative acts which are performed by the writer in the use of non-verbal elements. Initially; some theorical considerations are discussed. Then; a tentative taxonomy is a presented of the differente combinations of verbal and non-verbal elements through which the writer can organize his mensage. the las section deals with the rhetorical use of illustrations; and; finally; other fuctions; chich non-verbal elements con fulfill are suggest and supported.