The influence of lexical features on human rater's judgement of essay performance on local English Placement Test
This study explored to what extent the prompts may affect lexical features and whether lexical features could distinguish essays that were rated as different proficiency levels in the integrated reading-writing tasks. At the University of Illinois at Urbana-Champaign, 262 essays from the English Placement Test (EPT) were collected and holistically scored based on the EPT holistic profile-based rating scales into five profiles across three proficiency levels. Lexical features related to lexical sophistication and lexical diversity were investigated in relation to the profiles and proficiency levels. Lexical sophistication with commonly used words and academic words was measured through a computer program, called RANGE, that could produce the Lexical Frequency Profile (LFP) (Laufer & Nation, 1995). Lexical diversity was measured through five indices, TTR, Maas’s a2 (Mass, 1972), vocd-D (Malvern & Richards, 1997), HD-D (McCarthy & Jarvis, 2007) and MTLD (McCarthy & Jarvis, 2010). The results of this study showed that the prompts affect lexical features significantly, probably because of writers’ familiarity with different topics. Lexical sophistication related to commonly used words and academic words could both be used to significantly distinguish essays across proficiency levels and between profiles. High proficient writers were found to use more infrequent words and more academic words. As for indices measuring lexical diversity, this study indicated that none showed significant differences across proficiency levels or between two profiles. These results indicated that indices related to lexical sophistication may be a good indicator of lexico-grammar features as reflected in the EPT rating scales, while lexical diversity may not be a potential indicator.
English Placement Test, Lexical Diversity, Lexical Sophistication, Writing Assessment
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign