Can IELTS writing scores predict university performance? Comparing the use of lexical bundles in IELTS writing tests and first-year academic writing

Abstract

The Cambridge-based International English Language Testing System (IELTS) test is commonly used as one of the criteria in granting students admission to South African universities. It is therefore expected that the language structures elicited by the IELTS tests are representative of the language required in academic writing. Investigating aspects of language, such as the lexicon, should help to assess the validity of the IELTS test as a predictor of university performance. Lexical bundles are groups of words that frequently co-occur and therefore form recognisable clusters that become associated with particular styles of writing. Given that there are marked differences in the use of bundles both within genres and within academic disciplines, university students need to master the lexical bundles particular to their fields in order to display proficiency in the subject in their writing. The study reported on in this paper is based on a corpus of IELTS Task 2 writing tests as well as a corpus of essays, both of which were written by the same first-year psychology students. These corpora were developed to investigate the lexical bundles typical of these two types of academic genres in order to determine the degree of overlap, and therefore assess the validity of Task 2 of the IELTS test as a measure of the style of writing expected from undergraduate students. An analysis of the most frequently occurring 4-word lexical bundles within each corpus was conducted using WordSmith Tools, a computer programme designed for the investigation of aspects of vocabulary within large bodies of texts. The findings show that there are considerable differences in the lexical bundles used as a result of different basic requirements within each essay type. While Task 2 of the IELTS test requires students to present an opinion-based argument, academic essays are based on a number of sources obtained from the relevant literature. Consequently, following from the categorisation of lexical bundles reported in the literature, the lexical bundles in the IELTS test were found to be typical of spoken discourse, whereas those in academic essays are typical of written discourse. A possible implication of this finding is that the current style of the IELTS Task 2 writing test does not serve as a suitable predictor of university performance.