Despite growing interest in the studies on Zone of Proximal Development (ZPD), its operation in the forms of individualized and group-wide has been controversial. To cast some empirical light on the issue, this study was designed to quantitatively and comparatively study the applicability of the two scenarios of ZPD-based instructions to the writing complexity of Iranian EFL learners in terms of learners' types (low vs. high scorers). To this end, 118 EFL learners identified as homogeneous based on the TOEFL ITP test were randomly assigned into two equal experimental groups (individualized ZPD-and group-wide ZPD-based groups) which respectively received compatible instructions utilizing conference writing (as an individual scaffolding technique) and low-and high-structured writing templates (as a whole-class scaffolding technique). The treatments were allocated to the groups in a random manner within homogeneous blocks. Prior to and after the treatments, three tests (two writing tests and one ZPD test) were administered to measure both groups’,writing complexity and their ZPD levels. A ZPD test was also administered in the mid of treatments. The non-parametric analysis of covariance (ANCOVA) revealed that the individualized-ZPD-based instruction is constructive to the writing complexity of the low scorers, while the group-wide ZPD-based instruction shows not much constructive to the writing complexity of the high scorers. The findings pointed to the use of ZPD-based instructions in TEFL writing in meaningful contexts and thereby showing impacts made on the writing complexity of learners. The study, indeed, yields support to the feasibility of group-wide ZPD measurement along with an individualized ZPD approach.

This study examined the effect of the ZPD-based discourse scaffolding on EFL learners' co-construction of L2 metadiscourse performing collaborative writing tasks and explored the discourse scaffolding dynamics. The participants were 160 EFL students that were assigned to four different treatment conditions: (i) formal teaching, (ii) input enhancement, (iii) non-ZPD interaction, and (iv) ZPD-based L2 discourse scaffolding. The ZPD learners were required to audio-record their task-focused social interactions and also write four weekly compositions and one delayed essay. The results showed a substantial effect for the ZPD-based L2 discourse scaffolding on the ZPD participants' use of English metadiscourse. Further, the microgenetic analysis of the social interactions revealed that the ZPD groups employed manifold scaffolding dynamics at various ZPD levels to expedite task performance and their peers' use of L2 metadiscourse. The asymmetrical discourse construction grew mutual with the less capable peers offering increasingly more self-initiated repairing moves within their activated ZPD. Also, the students' essays were rated as more reader-friendly over time. Finally, the implications for L2 research and pedagogy are discussed.

Researchers have suggested that interactional feedback which is between teacher and learner during their writing is associated with L2 learning because it prompts learners to notice L2 forms. This paper reports a classroom-based study that investigated the role of feedback in socio-cultural theory. In this study, 12 EFL learners performed on three writing tasks and were provided with a three-stage procedural corrective feedback which started with metalinguistic implicit feedback and moved to metalinguistic implicit-explicit feedback and finally explicit correction by the teacher. Feedback was provided to learners in response to their written problems with past tense forms, subject-verb agreement, and countable and uncountable nouns. Learners' noticing of their written errors was assessed through verbal recall protocols based on their journals. Their attitude towards the procedural feedback was also checked through their reports. The findings suggested that despite being at the same level of proficiency as determined by the placement test of the language school, each learner noticed the errors at one of the three stages of the implicit-explicit feedback based on his/her ZPD.

One of the theories accounting for pragmatic development of L2 learners is Vygotsky’s (1978) sociocultural theory. This study investigated the development of EFL learners' pragmatic competence through the lens of an important concept of Vygotsky’s theory, i.e. the zone of proximal development. The study was conducted to answer two questions. The first question was whether the amount of scaffolding provided to EFL learners would have any relationship with their proficiency level. The second question was focused on the investigation of the relationship between learners’ individual ZPDs and the group ZPD. To this end, 20 EFL learners at low vs. high proficiency levels were selected and assigned randomly into two groups. Both groups received ZPD-sensitive instruction to produce the two speech acts of request and apology. The findings indicated no significant relationship between the proficiency level of the participants and the amount of scaffolding given for the production of the two speech acts. However, the findings revealed certain relationship between participants' individual ZPDs and their group ZPD. This study suggests that EFL learners' general language proficiency has little impact on the development of their pragmatic competence. Besides, based on the findings, scaffolding seems to have learner-specific effects, meaning that each learner may need a specific amount of scaffolding for his/her ZPD to grow despite being in the same group ZPD.

Central to Vygotsky-inspired sociocultural theory (SCT) is the notion of zone of proximal development (ZPD) seen by several SLA researchers as a very useful framework within which L2 teaching and learning can take place. Van Lier (2004) argues that the ZPD could be activated in diverse proximal contexts (PCs) and is not limited to the expert-novice scenario. This study probed whether Iranian EFL learners' collaborative task performance within different ZPD-based PCs results in their development of interactional competence (IC). Young's (2011) IC model was used for constructing and developing an IC test (ICT) which was used at the pre-test and post-test times. Three intact EFL listening-speaking classes at a university at southwest of Iran were randomly assigned to the expertnovice, equal peers, and control (non-ZPD) conditions. The coconstructed interactions of the groups in (a) symmetrical ZPD based conditions were audio-recorded and further analyzed for traces of participants' L2 IC development. A triangulation (quantitative and micro-genetic) approach was adopted analyzing the data. The results showed that whereas both the ZPD groups (equal-peers and expert-novice) outperformed the non-ZPD group on the IC posttests, no statistically significant difference was found between participants' IC development in symmetrical and asymmetrical ZPD-based PCs. Further, the micro-genetic analysis of the ZPD groups' interactions demonstrated how participation and activity in different PCscan effectively trigger awareness of mechanisms and norms of L2 spoken interaction and, in turn, result in IC development. The findings point to the applicability of diverse ZPD-adjusted PCs, composed of equal or unequal participants, in EFL classrooms and also the efficacy of ZPD-based interactive scenarios for students' development of IC in a second language.