The purpose of this study was to investigate the effect of three types of task planning on accuracy of Iranian EFL learners' oral production. In this study planning was operationalized at three levels: rehearsal, strategic and unpressured within-task planning. The oral presentation task was employed as the means of data collection. The subjects consisted of forty advanced students in four classes with the same level of language proficiency (N=10). One class was randomly selected to act as the

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... ntrol and three others selected as the experimental groups. In order to collect the data, the oral presentation task was used as the means of data collection. In the first group participants were asked to perform the task two times with two-week interval between the two performances. Participants in the second experimental group received strategic planning with ten minutes of planning time. Whilst the participants in the third group began their oral presentation immediately but took time as long as they like to performed their presentation. The participants in the noplanning group, were asked to perform their presentation immediately after reading each text within a limited time. Performance was assessed through the percentage of error-free clauses (to measure accuracy). Data analysis showed a positive influence of both rehearsal and unpressured within-task planning on accuracy of L2 output. Also the results were greater in rehearsal group than within task group. Index Terms-rehearsal planning, strategic planning, within-task planning