Lexical Richness and Academic Writing Performance in a Thai University Academic English Test
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Abstract
Although lexical richness is an important feature of L2 writing quality, research on its predictive ability in university entrance tests, particularly in the Thai EFL context, is limited. Following Read’s (2000) framework, this study analyzes the relationship between lexical richness and academic writing performance in an academic English test at a Thai university. The study aims to (1) compare lexical richness characteristics across proficiency levels; (2) examine their relationship with writing scores; and (3) determine their predictive power independent of text length. A corpus of 103 argumentative essays was analyzed using TAALED and TAALES. The essays were classified into two groups based on university admissions criteria. The Meets Standard Group outperformed the Below Standard Group on text length (d = 1.54), lexical diversity as measured by HD-D (d = 0.76) and MATTR (d = 0.75), and bigram frequency (d = 0.47), but not on the Maas index, lexical density, word frequency (KF and BNC written), word range, and AWL proportion. Text length correlated most strongly with scores, followed by HD-D, MATTR, and bigram frequency, while other indicators did not reach significance. Regression analysis showed that, when text length was controlled, the model explained 64.8% of the variance, with text length as the dominant predictor (β = .691). Lexical diversity (HD-D) retained a small but significant independent effect (β = .174, p = .010), whereas lexical sophistication (bigram frequency, BNC written frequency, AWL proportion) and lexical density did not. These findings provide empirical evidence from the Thai EFL context for vocabulary instruction and rubric design.
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Benjamini, Y., & Hochberg, Y. (1995). Controlling the false discovery rate: A practical and powerful approach to multiple testing. Journal of the Royal Statistical Society: Series B (Methodological), 57(1), 289–300. https://doi.org/10.1111/j.2517-6161.1995.tb02031.x
Biber, D., & Gray, B. (2016, May 5). Grammatical complexity in academic English: Linguistic change in writing. Cambridge University Press. https://doi.org/10.1017/CBO9780511920776
Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Lawrence Erlbaum Associates.
Covington, M. A., & McFall, J. D. (2010). Cutting the Gordian knot: The moving-average type-token ratio (MATTR). Journal of Quantitative Linguistics, 17(2), 94–100. https://doi.org/10.1080/09296171003643098
Coxhead, A. (2000). A new academic word list. TESOL Quarterly, 34(2), 213–238. https://doi.org/10.2307/3587951
Coxhead, A. (2012). Academic vocabulary, writing and English for academic purposes: Perspectives from second language learners. RELC Journal, 43(1), 137–145. https://doi.org/10.1177/0033688212439323
Engber, C. A. (1995). The relationship of lexical proficiency to the quality of ESL compositions. Journal of Second Language Writing, 4(2), 139–155. https://doi.org/10.1016/1060-3743(95)90004-7
Faul, F., Erdfelder, E., Buchner, A., & Lang, A. G. (2009). Statistical power analyses using G*Power 3.1: Tests for correlation and regression analyses. Behavior Research Methods, 41(4), 1149–1160. https://doi.org/10.3758/BRM.41.4.1149
Field, A. (2018). Discovering statistics using IBM SPSS statistics (5th ed.). SAGE.
Hasko, V. (2022). The categorization of lexical errors in written L2 English: Measuring lexical accuracy. In A. Leńko-Szymańska & S. Götz (Eds.), Complexity, accuracy and fluency in learner corpus research (pp. 159–180). John Benjamins. https://doi.org/10.1075/scl.104.07hof
Hyland, K. (2003). Second language writing. Cambridge University Press.
Hyland, K. (2016). Teaching and researching writing (3rd ed.). Routledge.
Hyland, K., & Tse, P. (2007). Is there an "academic vocabulary"? TESOL Quarterly, 41(2), 235–253. https://doi.org/10.1002/j.1545-7249.2007.tb00058.x
Jarvis, S. (2002). Short texts, best-fitting curves and new measures of lexical diversity. Language Testing, 19(1), 57–84. https://doi.org/10.1191/0265532202lt220oa
Koo, T. K., & Li, M. Y. (2016). A guideline of selecting and reporting intraclass correlation coefficients for reliability research. Journal of Chiropractic Medicine, 15(2), 155–163. https://doi.org/10.1016/j.jcm.2016.02.012
Kyle, K., & Crossley, S. A. (2015). Automatically assessing lexical sophistication: Indices, tools, findings, and application. TESOL Quarterly, 49(4), 757–786. https://doi.org/10.1002/tesq.194
Kyle, K., Crossley, S. A., & Berger, C. (2018). The tool for the analysis of lexical sophistication (TAALES): Version 2.0. Behavior Research Methods, 50(3), 1030–1046. https://doi.org/10.3758/s13428-017-0924-4
Kyle, K., Crossley, S. A., & Jarvis, S. (2021). Assessing the validity of lexical diversity using direct judgments. Language Assessment Quarterly, 18(2), 154–170. https://doi.org/10.1080/15434303.2020.1844205
Kyle, K., Crossley, S. A., & Jarvis, S. (n.d.). TAALED: Tool for the automatic analysis of lexical diversity [Computer software]. https://pypi.org/project/taaled/
Laufer, B., & Nation, P. (1995). Vocabulary size and use: Lexical richness in L2 written production. Applied Linguistics, 16(3), 307–322. https://doi.org/10.1093/applin/16.3.307
McCarthy, P. M., & Jarvis, S. (2007). vocd: A theoretical and empirical evaluation. Language Testing, 24(4), 459–488. https://doi.org/10.1177/0265532207080767
McCarthy, P. M., & Jarvis, S. (2010). MTLD, vocd-D, and HD-D: A validation study of sophisticated approaches to lexical diversity assessment. Behavior Research Methods, 42(2), 381–392. https://doi.org/10.3758/BRM.42.2.381
Read, J. (2000). Assessing vocabulary. Cambridge University Press.
Sermsook, K., Liamnimitr, J., & Poonpon, K. (2017). An analysis of errors in English sentences: A case study of Thai EFL students. English Language Teaching, 10(3), 101–110. https://doi.org/10.5539/elt.v10n3p101
Simpson-Vlach, R., & Ellis, N. C. (2010). An academic formulas list: New methods in phraseology research. Applied Linguistics, 31(4), 487–512. https://doi.org/10.1093/applin/amp058
Srisawat, C., & Poonpon, K. (2023). Revision of an academic English writing rubric for a graduate school admission test. PASAA Journal, 65, 234–262. https://doi.org/10.58837/CHULA.PASAA.65.1.9
Thongyoi, K., & Poonpon, K. (2019). An investigation of syntactic complexity in essays written by test takers of Khon Kaen University Academic English Language Test (KKU-AELT). In Proceedings of the International Conference on English Language Studies 2019 (ICELS 2019) (pp. 27–34). Khon Kaen University.
Torruella, J., & Capsada, R. (2013). Lexical statistics and typological structures: A measure of lexical richness. Procedia – Social and Behavioral Sciences, 95, 447–454. https://doi.org/10.1016/j.sbspro.2013.10.668
Wang, S. (2011). Analyzing lexical richness in CET-4 Range Finder. Journal of Chongqing University of Posts and Telecommunications (Social Science Edition), 23(6), 104–110. https://doi.org/10.3969/J.ISSN.1673-8268.2011.06.021
Weigle, S. C. (2002). Assessing writing. Cambridge University Press.
Zenker, F., & Kyle, K. (2021). Investigating minimum text lengths for lexical diversity indices. Assessing Writing, 47, Article 100505. https://doi.org/10.1016/j.asw.2020.100505
Zhang, X. (2022). The relationship between lexical use and L2 writing quality: A case of two genres. International Journal of Applied Linguistics, 32(3), 371–396. https://doi.org/10.1111/ijal.12420
Zhang, X., & Ren, J. (2018). A comparative study in lexical richness between high and low score L2 impromptu compositions. Journal of Beijing International Studies University, 40(4), 41–52. https://doi.org/10.12002/j.bisu.156
