Unraveling the differential effects of task rehearsal and task repetition on L2 task performance: the mediating role of task modality

Abstract The study reported in this paper examined the differentiating effects of rehearsal and repetition, as two distinct task-readiness conditions, on L2 performance, and examined how such effects interact with modality (i.e., oral and written). To do so, 104 EFL learners were randomly divided into four groups, each with a unique readiness condition (rehearsal versus repetition) and a different performance mode (oral versus written). All groups performed orally or in writing a task twice either with awareness of the second performance (rehearsal) or without such anticipation (repetition). The task performances were assessed in terms of complexity, accuracy, lexis, and fluency (CALF). Findings indicated that while both readiness conditions showed beneficial effects, only rehearsal led to statistically significant enhancements in all CALF dimensions over time. Results also revealed that rehearsal yielded significant improvements across both modalities; however, the benefits were more evident in the writing mode. The study provides teachers with more insights into task implementation.