Measuring and perceiving changes in oral complexity, accuracy and fluency

This paper reports a case study of the nature and extent of progress in speaking skills made by a group of upper intermediate instructed learners, and also assessors’ perceptions of that progress. Initial and final interview data were analysed using several measures of Grammatical and Lexical Complexity, Language Accuracy and Fluency. These interview excerpts were also rated by four International English Language Testing System (IELTS) test assessors. Results concerning performance changes and the relationship between objective measures and the assessors’ ratings are reported.The results suggest that all subjects improved with regard to one or more of the four performance features examined, though gains on subjective ratings were mostly low. Certain objective indices appeared sensitive to short-term gains and differences in adjacent proficiency bands. These indices included three general Complexity metrics, a general and specific Accuracy measure, and three temporal Fluency measures. Implications for oral rating are discussed.