SUMMARY
One of the influential concepts of sociocultural theory in language acquisition research is the zone of proximal development, which is an opportunity for language learners to develop their capacities. It is believed that the learner’s language development happens through scaffolding in language learning (Bruner, 1983). This study relies on the scaffolding technique to investigate the effect of three forms of scaffolding process, namely teacher, class, and peer scaffolding, on the writing development of EFL learners. To do this, an intact group sample of 30 participants was selected. The participants were doing their essay writing course in which 19 of them were in one class, assumed as the experimental group in the study, and 11 were in another, assumed as the control group. To maintain possible homogeneity of the participants, an Oxford Placement Test was administered to both groups. The experimental group practiced the techniques of teacher, class, and peer scaffolding in three consecutive sessions respectively, while the control group practiced three individual techniques. After analyzing the mean of the total scores in addition to inter-rater reliability, the multivariate tests, on the quantitative analysis, showed that the control group outperformed the experimental group. For further understanding of the reasons, on the qualitative analysis, the talks in the experimental group were analyzed. Finally, the findings of both quantitative and qualitative methods of analysis are discussed.