# Removing Bias and Incentivizing Precision in Peer-grading

arXiv: https://arxiv.org/abs/1807.11657 · HTML: https://mlsanity.com/paper/1807.11657/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 31 Jul 2018.

## Built on by (most cited first, 2 of 2)

- [Manipulation and Peer Mechanisms: A Survey](https://mlsanity.com/paper/2210.01984/) (2022)
- [Rank It, Then Ask It: Input Reranking for Maximizing the Performance of LLMs on Symmetric Tasks](https://mlsanity.com/paper/2412.00546/) (2024)

## Abstract (arXiv)

We study peer-grading with competitive graders who enjoy a higher utility when their peers get lower scores. We propose a new mechanism, PEQA, that incentivizes such graders through a score-assignment rule which aggregates the final score from multiple peer-evaluations, and a grading performance score that rewards performance in the peer-grading exercise. PEQA makes grader-bias irrelevant. Additionally, under PEQA, a peer-grader's utility increases monotonically with the reliability of her grading, irrespective of her competitiveness and how her co-graders act. In a reasonably general class of score assignment rules, PEQA uniquely satisfies this utility- reliability monotonicity. When grading is costly and costs are private information, a modified version of PEQA implements the socially optimal effort choices in an equilibrium of the peer-evaluation game. Data from our classroom experiments confirm our theoretical assumptions and show that PEQA outperforms the popular median mechanism.
