From the dissertation blog:

At the conclusion of grading each semester, I review the success of self-assessment (and, if applicable, self-evaluation/grading) in the course(s) I teach.

This semester I taught English 502 (2nd-year Intro to Tech Writing). 17 students. This course was roughly a 3 on my 5-point scale of self-assessment (or maybe a 3.5): students submitted a sequence of self assessment documents – there were two: a midterm and a final; received direct, actionable feedback on at least one of them; and were involved directly in the grading process.

Results:
Out of the final grades that the 17 students proposed for themselves, I disagreed slightly with six. The other 11 were in agreement in terms of the overall grade, though the exact breakdown of point totals might have differed in places.

Out of the six disagreements, two underestimated (I substituted my own higher grade for both) and four overestimated (I substituted my lower grade for two of these). Of the four I judged to be overestimations, one was due simply to improper math — the student was fine with my overriding grade once I explained it. Two were justifiable enough for me to let them stand. The remaining student was mildly disappointed but seemed to understand why I overrode the proposed final grade.

None of the 502 self-given grades was any more than 1/3 of a grade point different from the assessment I had in mind (B+ versus A-, C+ versus C, etc.).

Were the slight discrepancies worth the benefits of the self-assessment system? Absolutely.

What would I change? Though many students seemed to have a good sense of their grades, not everyone offered a fully articulated self-assessment, suggesting that they might be able to recognized accepted grade levels without necessarily being able to step back and view themselves as writers, their final products, their processes, their collaboration, and their level of responsibility as students. More class discussion of the ways writing is judged and evaluated, as well as more self-assessment checkpoints throughout the semester, would help.