Student-centered assessment allows for collaboration between students and between the students and the instructor. It also allows for diverse talents and learning styles and should foster continued practice of learned skills.
If students self-assess using the rubric and a peer provides feedback using the same rubric, the student will more completely understand the expectations of the instructor and objectives of the project.
Self- and peer-assessments provide for the development of constructive criticism in a formative environment, allowing for reflection, clear thinking, and motivation to improve.