Comparative Effects of Recast and Metalinguistic Corrective Feedback in Processing Instruction versus Meaningful Output-based Instruction on the Acquisition of Comparative and Superlative Adjectives

Abstract

The present study intended to investigate the possible effects of two different types of implicit and explicit corrective feedback (recast and metalinguistic corrective feedback) and two types of grammar instruction, that is Processing Instruction (PI) as an input- based approach and Meaningful Output- Based Instruction (MOBI) with output orientation on learners' acquisition of comparative and superlative adjectives. To this end, 120 participants selected out of 140 Iranian freshman EFL learners, who had taken the pre-university English course, took part in the study. They were assigned into two main instructional groups (PI/ MOBI), each divided into two subgroups, one exposed to metalinguistc corrective feedback and the other to recast one. First, a pretest was administered to determine whether the possible effects gained at the end of the experiment resulted from the treatment itself or was partly due to some prior knowledge of learners. Two weeks after administering the pretest, the treatment started out and the study groups received the instruction of the target structures. At the end of the treatment, the students were given a posttest. The gathered data were analyzed through three independent samples t- tests. The results revealed that learners receiving recast in PI group outperformed their counterparts receiving metalinguistic feedback in the same group. Conversely, learners receiving metalinguistic feedback in MOBI group showed higher grammatical gains than those who received recast. Concerning the general effectiveness of two instructional models, no statistically significant difference was found, though PI group performed better than MOBI one. In sum, this study confirmed the view that providing the opportunity for giving feedback in juxtaposition with the instructional approach triggers noticing the gap between interlanguage and the target forms, which in turn improve the acquisition of L2 grammar.