This quasi-experimental quantitative research investigated the roles of computer-mediated and conventional written corrective feedback in enhancing Iranian high school EFL learners’ spelling knowledge. 74 male high school students ranging from 15 to 16 were selected randomly and assigned into two experimental and one control groups. The first experimental group received computer-mediated written corrective feedback while the second experimental group were given conventional (pen and paper) corrective feedback. However, the control group didn’t receive any written corrective feedback at all. Data were collected within five treatment sessions and via a pre-test, post-test, and delayed-post-test. For each treatment session, the participants were provided with a picture description task involving ten pictures and were asked to write the appropriate spellings by either typing them through computers or writing on a paper. Findings indicated that (1) written corrective feedback (WCF) significantly affected enhancing participants’ spelling knowledge, (2) computer-mediated written corrective feedback improved learners’ spelling proficiency, (3) conventional written corrective feedback significantly affected promoting EFL learners’ spelling proficiency, and (4) conventional written corrective feedback was much more effective than computer-mediated feedback in enhancing participants’ spelling knowledge. This study would hopefully pave the way for academics to gain deeper insights into computer-assisted instruction experience in Iran and improve its implementation afterwards.

Keywords: Computer-mediated corrective feedback, Conventional corrective feedback, Iranian EFL learners, spelling knowledge, written corrective feedback (WCF).