University of Tabriz Journal of English Language Teaching and Learning 2251-7995 13 28 2021 11 22 The Joint Effects of Teacher-led and Collaborative Planning conditions and Task Complexity on L2 Oral Production 217 242 14012 10.22034/elt.2021.46449.2401 EN Sanaz Mohazabieh Department of English Language,, Islamic Azad University, Shiraz Branch, Shiraz,, Iran. Rahman Sahragard Department of Foreign Languages and Linguistics, , Shiraz University , Shiraz, Iran. Ehsan Rassaei Majan University College, Muscat, Oman. Mustafa Zamanian Department of English Language, Islamic Azad University, Shiraz Branch, Shiraz, Iran. Journal Article 2021 06 08 This quantitative study aimed to investigate the combined effects of two types of strategic planning, namely collaborative and teacher-led planning conditions and task complexity on Iranian intermediate language learners' oral production in terms of complexity, accuracy, and fluency. To achieve this purpose, 90 EFL learners were selected through convenience sampling from a language institute in Shiraz, Iran, and randomly assigned to two control and four experimental groups. The study adopted a quasi-experimental design in the form of pretest, treatment, and posttest. In the first step, all participants took part in a speaking pretest in which they were required to narrate a story based on a series of picture description tasks. While the experimental groups underwent 10 treatment sessions of picture description task performance along with two planning types i.e., teacher-led and collaborative planning conditions, the control groups were not allowed to plan the task performance. In the last session, the language learners took a posttest whose results were compared with those of the pretest. The findings revealed that the language learners in the collaborative planning groups outperformed the other groups in terms of both fluency and complexity. Further, teacher-led groups did better than the other groups in terms of accuracy. This study carries crucial implications for EFL teachers, material developers, syllabus designers, and speaking skill examiners. https://elt.tabrizu.ac.ir/article_14012_e28657997bdb3fa9413ba6deb52211d2.pdf