Complexity, accuracy, and fluency in the argumentative writing of ESL and EFL learners

Abstract Despite the growing body of research on the complexity, accuracy, and fluency (CAF) in second language writing, differences in CAF across ESL and EFL learner productions remain underexplored. Thus, this study sought to determine whether there is a systematic difference in the CAF of English writing among ESL and EFL college students. For this purpose, a total of 1,870 essays were collected from the International Corpus Network of Asian Learners of English-Written or ICNALE-Written. The findings reveal different patterns in various measures of CAF in the written outputs of both the ESL and EFL groups. These findings suggest that writing complexity, accuracy, and fluency are not only influenced by proficiency level but also by learners’ L1 background. Findings further show moderate to high positive correlations between and among the components of each language dimension (i. e. complexity, accuracy, and fluency). Implications for ESL writing pedagogy and future studies are discussed.