Along with the critical language testing movement, test-takers are encouraged to have a more prominent role in their own assessment. The assumption here is that when learners find their voice, the outcome of assessment would be more valid and consequently it can be relied upon. Therefore, the present study conducted in an EFL writing assessment context sought to investigate whether sharing the rating scale, upon which the writing samples are rated, with the student writers bears any effect on the writing performance of the learners in the long run. For this aim, a body of sixty-four students was randomly assigned into a control and an experimental group. Writers in the experimental group were regularly informed about the rating scale used to rate their writings. Further, they received detailed feedback based on the scale. But, students in the control group had their ordinary writing classes. They were just informed about the final outcome of their compositions. Upon eight weeks of instruction, findings of a T-Test showed that learners in the experimental group significantly outperformed those in the control group. The obtained results confirmed the effectiveness of learners’ involvement in the rating process. It also underscored the notion of fairness in writing assessment.