the effect of mixed and matched level dyadic interaction on iranian efl learners’ comprehension and production of requests and apologies

Drawing upon sociocultural theory of vygotsky, the current study aims to investigate the effect of dyadic interaction in mixed and matched level proficiency pairings on comprehension and production of request and apology speech acts. the participants were 125 efl learners who were randomly assigned to control and experimental (interaction) groups. based on their scores in the pretest including a pragmatic listening test and an oral discourse completion test (odct), those in the experimental groups were assigned to the mixed (hl) and matched level (hh and ll) dyads. both the control and experimental groups received metapragmatic instruction on speech acts; however, the experimental groups were engaged in collaborative problemsolving tasks on speech acts for nine sessions. following the treatment, the posttest was administered, the results of which revealed the outperformance of the interaction groups compared with the control group. moreover, mixed level dyads were found to outperform their matched level counterparts in both measures of comprehension and production of speech acts. the findings have pedagogical implications for l2 teachers and practitioners on how to best pair learners in collaborative activities.