Modelling Second Language Performance: Integrating Complexity, Accuracy, Fluency, and Lexis

Complexity, accuracy, and fluency have proved useful measures of second language performance. The present article will re-examine these measures themselves, arguing that fluency needs to be rethought if it is to be measured effectively, and that the three general measures need to be supplemented by measures of lexical use. Building upon this discussion, generalizations are reviewed which focus on inter-relationships between the measures, especially between accuracy and complexity, since positive correlations between these two areas have been less common in the literature. Some examples of accuracy–complexity correlations are reviewed. The central issue here is how to account for these correlations, and so the…