lexical density

The literature on second/foreign language (L2/FL) discourse is replete with corpus-based studies into the use of various features representing lexical proficiency. Nonetheless, the lexical construct of English for academic purposes (EAP) texts developed by postgraduates majoring in teaching English as a foreign language (TEFL) still sounds like a relatively unexplored domain that merits further multi-dimensional investigation. To narrow the gap, the authors in the current study set out to evaluate the lexical richness of a corpus containing doctoral dissertations written by Iranian TEFL students in terms of lexical density, diversity, and sophistication. Taking advantage of the computational tool Coh-Metrix to analyze the lexical features, the corpus was analyzed in comparison with a first language (L1) baseline containing doctoral dissertations written by English native speakers. The comparative analysis of the L1 and L2 corpora revealed that the texts written by Iranian TEFL learners were lexically less diverse but more sophisticated. Additionally, the lexical density of the L2 corpus exceeded that of the L1 one in terms of nouns and adjectives. Based on the results drawn from a discriminant function analysis (DFA), the features representing lexical sophistication and density were found to be the best predictors of lexical richness since they could significantly discriminate between the two sub-corpora. The findings may provide new insights into the ways of evaluating and enhancing the lexical richness of FL/L2 written discourse.

In spite of numerous studies on the effect of AIAT on foreign language learning, few have examined its impact on university students’ academic writing proficiency over an extended period. This study, therefore, investigated the effect of Google Translate (GT) on the writing proficiency of English as a Foreign Language (EFL) university students. It examined fluency, lexical density, accuracy, and syntactic complexity across four versions of students’ writings: the pretest, writing with the aid of GT, the posttest, and a retention test conducted two to four months after the treatment. The findings indicated that syntactic complexity, accuracy, and fluency improved when students used GT for writing; however, these measures showed a significant decline in the posttest and retention test without GT. This decrease was more pronounced in lexical density and less so in syntactic complexity. Despite this decline, all factors assessed in the retention test still showed improvement compared to the pretest, indicating the positive effect of GT on students’ foreign language writing performance.