OICC Press Journal of English Language Pedagogy and Practice 2645-3584 17 1 2024 11 17 The Effect of Synchronous and Asynchronous Computer-Mediated Communication on Reading Comprehension and Reading Self-efficacy of Iranian EFL Learners 198 223 10.71586/jal.2024.09111183597 EN Azize Mahdavi گروه آموزش زبان انگليسي، واحد بناب، دانشگاه آزاد اسلامي، بناب، ايران Roya Ranjbar Mohammadi Department of English Language, Bonab branch, Bonab, iran Hasssan Assadollahfam Faculty of Humanities, Islamic Azad University Bonab Ali Abdollahi استادیار گروه ریاضی، واحد مراغه، دانشگاه آزاد اسلامي، مراغه، ايران Journal Article 2024 11 17 The current study aimed to investigate the effect of synchronous and asynchronous computer-mediated communication (CMC) on Iranian EFL learners’ reading comprehension and self-efficacy. To this end, 56 elementary EFL learners were assigned to one of the two experimental groups. Those trained in online video and audio instruction were assigned to the synchronous CMC group (N=27), while the participants who were taught through offline and recorded instruction were assigned to the asynchronous CMC group (N=29). Before and after the treatment, a questionnaire on reading self-efficacy and reading comprehension tests were administered. Independent samples t-test and Mann-Whitney U test were used to compare the reading comprehension and self-efficacy scores of the students in the two groups. Meanwhile, paired samples t-test and Wilcoxon test were used to do a within-group comparison of the pretest and the posttest scores. The findings showed that although both synchronous and asynchronous CMC significantly affected the reading comprehension and the self-efficacy of EFL learners, the synchronous instruction was more effective because the means of the synchronous group in the reading comprehension and self-efficacy posttests were higher than the means in the asynchronous group. This study has important implications for EFL teachers, EFL students, and syllabus designers.