Illuminating the Impacts of Contextual Diversity on L2 Writing Proficiency: A Corpus-Based Analysis in the Measures of Linguistic Complexity

Abstract The present study attempted to investigate the writing proficiency differences between the two groups of EFL and ESL writers considering the lexical, syntactic, and morphological complexity measures. Additionally, it aimed to disclose the association between writing proficiency and the utilization of the New General Service List (NGSL). To these ends, a corpus of 1331 argumentative essays accumulated from EFL and ESL writers on a single topic was examined. The findings of the analysis in the measures of linguistic complexity showed that the writings of the ESL group scored slightly higher than those of the EFL group in every corresponding sub-construct; that is, ESL writers were found moderately more proficient than EFL writers concerning the lexical, syntactic, and morphological complexity of their writings. However, the outcomes showed that EFL writers utilized more NGSL words in their essays, leading to the consideration that NGSL use may be negatively associated with proficiency levels. Hence, contextual diversity leads to distinct levels of proficiency, and lexical coverage can be considered a great indicator of writing skill and quality.