© 1992 by Oxford University Press
Articles |
Definitions in Science Lectures
City Polytechnic of Hong Kong
This paper is an empirical study of the speech act of definition in science lectures. Definitions occurring in sixteen lectures by native speaker biology and chemistry lecturers to non-native speaker students were transcribed and coded onto a computer data base, according to twenty-eight linguistic and para-linguistic features. Data were obtained regarding frequency, distribution, function, and form of definitions. A total of 315 terms were defined, indicating an average frequency of occurrence of one definition per 1 minute 55 seconds. Definitions were found to fulfil one of two main functions: signposting the logical/discourse structure of the subject/lecture, or helping to maintain comprehension as the discourse progresses. Definitions were found to often cluster together in discourse, but there was no evidence of them being more frequent at the beginning of lectures. Definitions were classified into three major types and one minor type, each of the major types being further sub-classified. Findings are reported for ordering of the semantic elements of definitions, syntactic and lexical signalling devices, and various rhetorical and paralinguistic features which accompany definitions. A final section discusses implications for pedagogy.