Investigating the washback effects on improving the writing performance of Iranian EFL university student

Because of the complex nature of writing as a social, cultural and cognitive phenomenon, and the variety of challenges faced by both learners and teachers, learning and teaching writing in EFL context, this study aimed to investigate the washback effects on improving Iranian EFL students' writing performance. Two research questions were addressed. The first was whether the test-oriented writing classes provide teachers with a taxonomy of more common errors in university EFL learners' scripts or not. The second aimed at investigating the significance of the difference in the writing performance of university EFL learners receiving washback treatment and those taught by the traditional method. The subjects of the research were ninety Iranian university EFL students, making up two intact classes of thirdyear majors. There were forty-five students per class, which consisted almost entirely female. The control group continued the traditional way of practicing writing in the classroom. The experimental group received washback–based instruction. The instructional program was then steered toward improving the areas of difficulty and focusing on the aspects that require more practice. The study showed that the rate of grammatical and lexico-semantic errors was more than errors in keeping cohesion, coherence and rhetorical organization.The diagnostic instructional program based on washback effect was satisfactory in improving the students' writing performance