A comparative corpus study on lexical bundles and keywords in English language teaching dissertations written by English speaking writers and Thai writers of English

The purposes of this corpus-driven study were to compare the use of four-word lexical bundles in dissertations written by English speaking writers and Thai writers of English. Two specialized corpora, roughly 1,000,000 words apiece, were gathered from dissertations in the field of English Language Teaching. Each corpus was subdivided into three sub-corpora, namely, the Introduction, the Methodology, and the Results and Discussions sub-corpora. Two frameworks employed for the structural and functional analysis of the four-word lexical bundles were adapted versions of Biber et al.’s (1999) and Hyland’s (2008a) by Salazar (2011). The analysis of lexical bundles were performed using concordance software AntConc. The results showed that Thai writers of English overused lexical bundles in comparison with that of English speaking writers in each part of the dissertations, especially in the Results and Discussions section, which could result from institutional factors such as expectation and practice of Thai universities that expect Thai Ph.D. students to be more critical of the findings and to offer more implication. The structural analysis revealed the overuse of verb-structured lexical bundles throughout the three sub-corpora of Thai writers of English, which was likely to stem from the non-native speaker's failure to employ noun- and preposition-structured lexical bundles effectively. The proportion of functions of lexical bundles in each section of dissertations written by both groups of writers shared a relatively similar trend, indicating that both groups of writers conformed to the same convention of dissertation writing. The analysis of keywords revealed 60, 95, and 101 keywords integral to the lexical bundles in the Introduction, the Methodology, and the Results and Discussions sub-corpus of English speaking writers, respectively, whereas, 53, 132, 183 keywords were identified to be partial to the lexical bundles in the Introduction, the Methodology, and the Results and Discussions sub-corpus of Thai writers of English, respectively.