roles of task complexity, task repetition, recasts, and feedback timing in language development

The combined effect of cognitive task complexity and planning has recently been the focus of many studies. nevertheless, most of them have explored explicit planning (strategic planning) rather than implicit planning (task repetition, tr). the role of corrective feedback provided during simple and complex tasks or under the tr condition in l2 performance has also been investigated in a number of studies. however, to the best of the researcher’s knowledge, no study has been conducted to explore the impact of corrective feedback when both cognitive task complexity and task repetition are included. furthermore, feedback timing (immediate vs. delayed feedback) has never been examined in the realm of cognitive task complexity or task repetition. to bridge these gaps, the present study was designed to investigate the impact of task complexity in combination with task repetition, recasts (as a type of corrective feedback), and feedback timing on l2 development. to this end, 60 efl intermediate learners were chosen based on the preliminary english test. two treatment tasks (narrative tasks) were used. one of them was more cognitively demanding than the other one in terms of ±few elements based on robison’s triadic componential framework. the complexity levels of these tasks were verified through the affective variables questionnaire, stimulated recall interviews, and the time judgment task. all the participants took an assessment task and an error correction test as pretests. they then were randomly divided into two major groups (n= 30 each): the simple and complex groups performing the simple and complex tasks, respectively. half of the participants in each group received partial recasts in response to errors in the use of the present third-person singular verb forms during their first performance (immediate recasts). immediately after finishing their first performance, they re-narrated the task. the other half received partial recasts after the completion of the first performance. they were provided with the recorded parts of their first performance with errors in the linguistic target and received recasts. after that, they narrated the task again. they were administered an assessment task and an error correction test immediately after the second performance as immediate posttests. two weeks later, they were given an assessment task and an error correction test as delayed posttests. it is worth noting that different versions of the assessment tasks and error correction tests as well as the treatment tasks were counterbalanced. the results of the two-way anovas indicated that the provision of recasts accompanied by task repetition led to significantly higher scores in both immediate and delayed posttests. as for the immediate posttests, the repetition of less cognitively demanding tasks was significantly more beneficial, and providing recasts after the first performance gave rise to substantial improvements in using the 3rd person form. in the simple task, the provision of immediate and delayed recasts brought about approximately the same level of improvement. in the complex task, the target-like use of the present third-person form was considerably boosted when recasts were provided after the first performance (delayed recasts). concerning the delayed posttests, the highest scores were obtained for the delayed-recast condition in the simple task. the results are explicated through limited attentional capacity models, levelt’s model of production, and skehan’s trade-off hypothesis. the findings have implications for language teachers and material developers.