An examination of the impacts of variations in task cognitive complexity and task input format on L2 oral fluency, measured at the middle and end of clauses

Second language (L2) learners often state a desire to produce speech as fluently as first language (L1) speakers. However, it is still not completely clear how L2 oral fluency is understood, and neither is it consistent in how it is measured. The study investigates the differences in L1 and L2 speakers’ oral fluency across levels of task complexity and task input formats. Research has established that higher levels of task complexity return lower levels of spoken fluency. PSTM was also investigated to examine for any correlations between task design, task complexity, and oral fluency. Furthermore, investigating oral fluency at the middle and end of clauses will hopefully enable a better understanding of L2 speech production and the attendant mental processes. For this research project 80 participants’ performance on two narrative tasks were recorded: 40 English first language speakers and 40 Korean participants who speak English as a second language. Each participant performed two tasks differentiated by the level of cognitive complexity (operationalised through the chronological/random order of information) and the input format (pictorial or written). It was hypothesised that pauses occurring ‘within a clause’ (Skehan et al., 2016) are evidence of difficulties at the formulation stage of speech production (Levelt, 1999), while pauses occurring ‘between clauses’ provide evidence of problems during conceptualization. A phonological short-term memory (PSTM) test was used to examine the role it plays in mediating the effects of task complexity and task design on L2 fluency. The findings reveal that L2 speakers show evidence of significant increases in the frequency of pauses at the mid-clause when performing the cognitively more complex tasks. A strong negative correlation was evidenced between PSTM and the frequency of mid clause pauses. These findings are explained in terms of cognitive fluency, automaticity, and the processes of L2 speech production.