Many language teachers spend countless hours correcting student writing in hopes of improvement in accuracy, but as of yet, there has been little consensus regarding the efficacy of written corrective feedback (CF) or the type of CF that is most efficient. Although many studies have been conducted on the topic, conflicting results have arisen. In this meta-analysis, ten quasi-experimental studies of written corrective feedback are examined to analysis the overall effect of CF and compare the variations of CF. It is shown that written corrective feedback in general is inconclusive as a predictor of student improvement in writing over time and the efficacy of the feedback depends on its focus. It is also shown that focused written feedback has any overall positive effect on student's writing, whereas comprehensive written feedback has the potential to have a harmful effect on student's writing over time.