Research map / Large language models / Language, safety and interpretability
Benchmarking LLMs' Judgments with No Gold Standard
Read the paperCheck your idea against 108,967 papers
AI-extracted summary. Written by AI from the paper's full text. Numbers and claims can be wrong or missing context, so check the paper before you cite or build on it.
Proposes GEM, a generative mutual-information (PMI-based) metric that scores LLM outputs against non-gold peer references, plus GRE-bench for benchmarking LLM peer-review generation on ICLR 2023 data.
Problem
Evaluating open-ended, subjective LLM generations (e.g., peer reviews) when no gold-standard reference exists, while remaining accurate and resistant to superficial manipulations such as rephrasing or elongation.
Approach
Estimate the pointwise mutual information between a candidate response and a peer reference response using an LLM's token probabilities (log Pr(y|x) minus log Pr(y)), after preprocessing both texts to strip style; GEM-S conditions on a task synopsis (e.g., abstract) to count only additional semantic information.</µcore_idea>
Key results
- GEM-S achieves Spearman rho 0.479 with instructor grades vs 0.537 for GPT-4o LMExaminer; all other baselines except BARTScore-recall fail significant correlation.
- GEM and GEM-S show significant negative SMD on all three degradations (e.g., GEM-S -0.566 on abstract-only review), while LMExaminer fails to penalize abstract-only reviews (0.715).
- GEM and GEM-S show no significant score increase after GPT-4o rephrase, Llama-3.1 rephrase, or meaningless elongation, whereas LMExaminer increases significantly after all manipulations.
Measured effects reported in the paper
| What was changed | Where | Measured | Effect |
|---|---|---|---|
| Condition mutual information on the paper abstract (ablation) | GEM · Human-annotated peer grading | Spearman's ρ: 0.431 -> 0.479 | Helped |
| Remove response preprocessing (ablation) | GEM · Human-annotated peer grading | Spearman's ρ: 0.300 vs 0.431 | Hurt |
| Delete every other sentence from reviews | GEM and GEM-S · ICLR 2023 peer reviews | SMD: GEM: -0.401; GEM-S: -0.409 | Hurt |
| Delete sentences and complete them with GPT-4o | GEM · ICLR 2023 peer reviews | SMD: -0.308 | Hurt |
| Replace reviews with abstract-only fictitious reviews | GEM and GEM-S · ICLR 2023 peer reviews | SMD: GEM: -0.191; GEM-S: -0.566 | Hurt |
| Add fixed meaningless sentences to reviews | GEM · ICLR 2023 peer reviews | SMD: -0.063 | No clear effect |
| Add fixed meaningless sentences to reviews | LMExaminer · ICLR 2023 peer reviews | SMD: 0.105 | Helped |
| Rephrase reviews with GPT-4o or Llama-3.1 | GEM and GEM-S · ICLR 2023 peer reviews | SMD: GEM: -0.058, -0.107; GEM-S: -0.046, -0.114 | No clear effect |
| Use Llama-3.2 90B rather than GPT-4o for preprocessing (ablation) | GEM · Human-annotated peer grading | Spearman's ρ: 0.433 -> 0.274 | Hurt |
| Use Llama-3.2 90B rather than GPT-4o for preprocessing (ablation) | GEM and GEM-S · ICLR 2023 peer reviews: rephrase and elongation manipulations | SMD: GEM: 0.124, 0.138; GEM-S: 0.156, 0.112 | Mixed |
| Use Llama-3.2 90B rather than GPT-4o for preprocessing (ablation) | GRE-bench · ICLR 2023 model rankings | Spearman's ρ: GEM 0.89; GEM-S (abstract) 0.85; GEM-S (ASSW) 0.83 | No clear effect |
| Replace a review with a random review from another restaurant | GEM and GEM-S · Yelp reviews | SMD: GEM: -0.516; GEM-S: -0.283 | Hurt |
Surprising findings
- LMExaminer (GPT-4o) failed to penalize abstract-only fictitious reviews (SMD +0.715), while GEM-S penalized them strongly.
- GRE-bench scores with an 8B evaluator correlate highly with a 70B evaluator (Spearman 0.93 for GEM), suggesting small evaluation LMs suffice.
Limitations
- Theoretical guarantees rely on the LLM estimating the true conditional distribution accurately, which may not hold.
- Requires reference responses containing original human-generated information; LLM-only references can unfairly favor the generating model.
- Preprocessing model choice materially affects results (Llama-3.2 90B preprocessing lowers human correlation from 0.433 to 0.274 and weakens manipulation robustness).
Experimental setup
Datasets: ICLR 2023 peer reviews (OpenReview) Human-annotated proposal peer grading dataset (30 proposals, ~180 reviews) Yelp restaurant reviews
Benchmarks: GRE-bench (ICLR 2023) Human-annotated peer grading dataset Yelp restaurant reviews
Metrics: Spearman correlation standardized mean difference (Cohen's d) GRE-bench score
Baselines: BLEU ROUGE-L BERTScore BARTScore LMExaminer (GPT-4o) GEM-raw
Builds on: BARTScore GPTScore peer prediction information elicitation without verification LM-as-examiner
Closest papers by meaning
- Neither Valid nor Reliable? Investigating the Use of LLMs as Judges (NeurIPS 2025 · similarity 0.91)
- Prometheus: Inducing Fine-Grained Evaluation Capability in Language Models (ICLR 2024 · similarity 0.90)
- Accelerating Unbiased LLM Evaluation via Synthetic Feedback (ICML 2025 · similarity 0.90)
- RocketEval: Efficient automated LLM evaluation via grading checklist (ICLR 2025 · similarity 0.90)
- PiCO: Peer Review in LLMs based on Consistency Optimization (ICLR 2025 · similarity 0.90)
- RevisEval: Improving LLM-as-a-Judge via Response-Adapted References (ICLR 2025 · similarity 0.89)
Writing a paper in this area? scime draft is a free LaTeX editor with AI included, real-time co-authors and a check of your references and venue rules before you submit. It also imports OpenAI Prism projects.
