Inspired by Vygotsky’s Sociocultural Theory (SCT), the current study intended to investigate the effect of summary training (i.e., oral and written) on intermediate EFL learners’ reading comprehension in different conditions (i.e., individual and collaborative). Data collection tools and procedures encompassed PET test, First Certificate in English (FCE) reading pre-test, and post-test. First, to ensure that the instruments, scoring, as well as summary training procedures were reliable, the researchers conducted a pilot test. During the main study, 120 Iranian EFL intermediate male and female learners aged from 16-18 were considered as the main participants. Learners were divided into 6 groups (i.e., three individual and three collaborative conditions). Furthermore, each condition included three groups with oral summary, written summary groups, and no summary group. A post-test followed the treatment that lasted for 6 sessions. A series of ANOVA with follow up pair-wise comparisons and a series of independent-samples t-tests indicated that: (1) summary training, especially the oral one, was more effective in enhancing the EFL learners’ reading comprehension, and (2) members of the collaborative groups outperformed the members of the individual groups regarding their reading comprehension development. The theoretical and practical implications are discussed concerning enhancing the EFL learners’ reading comprehension.
