L2 fluency across tasks: disentangling demands on conceptualisation and formulation in speech production

Abstract Second language (L2) speaking research has highlighted intra-speaker variability of fluency performance across tasks. To better understand such task effects on fluency, the framework of speech processing demands has been proposed as a systematic approach to relating task characteristics to L2 speech production mechanisms and the limited capacity of attentional resources (Skehan 2009. Modelling second language performance: Integrating complexity, accuracy, fluency, and lexis. Applied Linguistics 30(4). 510–532, 2014. Limited attentional capacity, second language performance, and task-based pedagogy. In Peter Skehan (ed.), Processing perspectives on task performance, 211–260. Amsterdam: John Benjamins). However, the framework has been tested on a limited range of task types, using carefully designed experimental tasks. For the sake of the ecological validity of findings, the current study thus further explores how L2 learners’ fluency varies across four spontaneous speaking tasks differing in their processing demands. A total of 128 Japanese learners of English completed four speaking tasks: Argumentative task, Picture narrative task, Reading-to-Speaking task, and Reading-while-listening-to-speaking task. Their speech was analysed in terms of speed, breakdown, and repair fluency and was compared across tasks. The results of Generalised Linear Mixed-effects Modelling showed that conceptualising demands were reflected in the frequency of filled pauses, while formulation demands were associated with the articulation rate, mid-clause pause ratio, and mid-clause pause duration. These findings unveil the interrelationship between task characteristics, fluency measures, and how learners approach tasks.