Quantifying the Statistical Effect of Rubric Modifications on Human-Autorater Agreement

TL;DR

This study analyzes how modifications to evaluation rubrics influence agreement levels between human and automated raters, highlighting factors that improve or hinder consistency.

Contribution

It provides a statistical analysis of rubric modifications' effects on human-autorater agreement across different evaluation domains.

Findings

Rubrics with representative examples and added context increase agreement.

Reducing positional bias in rubrics improves consistency.

Higher rubric complexity and conservative aggregation decrease agreement.

Abstract

Autoraters, also referred to as LLM-as-judges, are increasingly used for evaluation and automated content moderation. However, there is limited statistical analysis of how modifications in a rubric presented to both humans and autoraters affect their score agreement. Rubrics that ask for an overall or \emph{holistic} judgment - for example, rating the ``quality'' of an essay - may be inconsistently interpreted due to the complexity or subjectivity of the criteria. Conversely, rubrics can ask for \emph{analytic} judgments, which decompose assessment criteria - for example, ``quality'' into ``fluency'' and ``organization''. While these rubrics can be edited to improve the individual accuracy of both human and automated scoring, this approach may result in disagreement between the two scores, or with the associated holistic judgment. Designing and deploying reliable autoraters requires understanding not just the relationship between human and autorater annotations but how that relationship changes as holistic or analytic judgments are elicited. The results indicate that rubric edits providing representative examples and additional context, and reducing positional bias in the rubric increased human-autorater agreement, while higher rubric complexity and conservative aggregation methods tended to decrease it. The findings from the automatic essay scoring and instruction-following evaluation domains suggest that practitioners should carefully analyze domain- and rubric-specific performance to move towards higher human-autorater agreement.