Despite the widespread use of Learner-Oriented Assessment (LOA) in (English as a Foreign Language EFL classes, concerns persist regarding its suitability for contexts such as Iran. Drawing on Carless's (SHE, 31:219-233, 2006) criteria for LOA, the present study examined the effectiveness of peer and teacher feedback in an academic writing course. To this aim, a total of 124 intermediate language learners who were homogenized in terms of language proficiency, based on the Common European Framework of Reference for Languages (CEFR), were randomly assigned to an experimental and a control group. A 12-session writing instruction course with specific writing tasks was developed. One group received feedback from peers, while the other group received feedback from the teacher. Findings revealed that peer feedback resulted in better writing in terms of language, content, and organization. It was also found that the peer feedback group could retain their learning in the long run. These findings underscore the effectiveness of peer feedback within the framework of LOA, particularly in teacher-directed settings.