Abstract

This study aimed at investigating the differential effects of three types of mediational artifacts (EMW, EDW, and EMDW) through the CBI approach on EFL learners’ expository writing and learning transfer of rhetorical genre. Therefore, 57 advanced students were randomly assigned into one of three mediational groups, namely EMW, EDW, and EMDW. Participants in the EMDW group were provided with all mediational mechanisms, including instructors’ oral deductive explanation of concepts, SCOBAs material, students’ demonstration of their understanding, and writing practices. However, in the EMW group, students received instructors’ explanations of concepts along with SCOBAs material and writing practices, while the EDW group was provided with students’ demonstrations of their understanding instead of SCOBAs material. After assuring homogeneity of the participants in three groups at the outset of the study with regard to their pre-task scores, the CBI was held over a course of three weeks on expository rhetorical structure. Data for the first research question was gathered through a post-task on expository writing after the treatment. Learners’ opinions were also reflected through a semi-structured interview after the post-task. To testify transferability of rhetorical structure, a delayed post-task was administered after one week. The obtained results indicated that three mediational conditions led to differential expository writing performance. Further improvement was determined in the EMDW group, followed by the EMW group. Furthermore, rhetorical transfer to a new writing task was significantly different among the groups, as the EMDW group could outperform the other groups. Finally, the satisfaction of participants toward CBI was reflected.