A Corpus-based Study On Lexical Cohesion Devices In Non-English Majors Writing

Taking Halliday & Hasan's (1976) text cohesion theory as its theoretical foundation and the theory of patterns of lexis proposed by Hoey (1991) as its working taxonomy, the present research traces the changes of the application of lexical cohesion devices used by non-English majors in compositions. The research questions are:a. Which lexical cohesion device(s) is/are the most commonly used device(s) in students'compositions, and which one(s) is/are the least used?b. What are the diachronic changes of the overall applications of lexical cohesion in students'compositions? Do they make progress?c. What are the diachronic changes of the applications of "reiteration" and "paraphrase" in students'compositions? Do they make progress?Based on the self-constructed corpus of 500 compositions written by 125 non-English major students in Grade 2006 at Beijing Forestry University in the four terms, the present quantitative research is conducted to study the diachronic changes of students'application of lexical cohesion devices by applying Microsoft Excel (2003 version), SPSS (15.0 version) and a self-developed WordNet-based (2.0 version) corpus analytical program in Python language (2.4.3 version). The major findings include:a. SLR-A is the most frequently used lexical cohesion device applied by students of non-English majors, CLR-B being the least frequently used.b. The sum of links used by students gradually increases in general. The sum of links used in Term 1 (T1) is significantly different from those used in Term 2 (T2) and Term 4 (T4), while the average link length does not vary greatly. c. In terms of reiteration, more and more links can be seen in general, in which significant change appears between Term 3 (T3) and T4. In terms of paraphrase, no significant difference can be seen among the sum of links in T2, T3 and T4 after it reaches the peak in T2.Based on the above findings, this paper further explores the factors which influence the application of lexical cohesion devices. It points out that lexical cohesion devices are topic-specific, and the advantages of Hoey's (1991) theory can be utilized to the full only when lexical cohesion matrices are used. Moreover, the research is intended to shed light on College English teaching so as to raise the teachers'and learners'understanding of lexical cohesion and improve the learners'English writing quality.