Critical thinking has been a significant issue in the realm of EFL teaching and learning. This study aimed at investigating the contribution of paper-based and web-assisted feedback on Iranian EFL learners’ level of criticality in acquiring the writing skill. Besides, it was endeavoured to explore the extent of feedback contributions to the five constituents of critical thinking. Accordingly, a non-randomized control group pre/post-test design was taken into consideration, accounting for the two experimental treatments along with one control group. The levels of critical thinking of 61 EFL learners were initially rated prior to the 11-session treatments, and finally were re-appraised at the termination of the semester at University of Hormozgan. The out-turns of the one-way between-groups ANOVA set forth a statistically significant difference between the critical thinking scores of the four groups with respect to the type of feedback they received. Moreover, the outcomes of paired samples t-test revealed a statistically significant increase in all the four within-group criticality scores from pretest to posttest. Furthermore, the results of MANOVA illuminated a significant feedback contribution to the argument level of critical thinking, substantially due to the web-assisted type. So, web-assisted feedback was concluded to play a crucial role in facilitating EFL learners' journey towards becoming more critical writers. Finally, some pedagogical implications were conveyed parenthetically.
