Fluency and structural complexity as predictors of L2 oral proficiency

Automaticity and real-time aspects of performance are directly relevant to L2 spoken language proficiency. This paper analyzes data from L2 speakers of English and Spanish spread over a range of proficiency levels as identified by traditional holistic, rubric-based human ratings. In spontaneous speech samples from these L2 populations, we studied timed measures of spoken fluency (linguistic units per time) that co-vary with proficiency level and compared the timed measures to indices of the linguistic complexity of the same spoken material. Results indicate that duration-based fluency measures yield as much or more information about proficiency as do structural complexity measures. These empirical findings suggest that expert perception of oral proficiency relate to automatic, real-time aspects of speaking and that the oral proficiency construct may be enriched by adding timing to its communicative/functional framework.