JEV-as-a-Judge: Accept When Confident, Escalate When Unsure

Yubo Li, Yidi Miao, Ramayya Krishnan, Rema Padman

Carnegie Mellon University

Published September 22, 2026 · on the feed September 23, 2026 · ▲ 41 · arXiv 2609.26550

Evaluation & judging No code arXiv ↗Hugging Face ↗

The abstract

LLM-as-a-judge enables evaluation across diverse tasks, but inference cost and confidence reliability become critical at scale. We study whether a decision-only judge can provide an economical first pass and identify when stronger evaluation is needed. Comparing jev-as-a-judge with sixteen generative and reward-model judges, with blinded human adjudication, we find it within three percentage points of a state-of-the-art LLM judge, our strongest comparator, on ordinary preference and evidence-grounded factuality at 0.36% of the comparator's fee. Larger gaps arise when judgments require checking a derivation or resisting an elaborately written wrong answer. On several benchmarks, JEV's gap to this comparator is concentrated in low-confidence decisions. A frozen cascade that accepts confident verdicts and escalates uncertain ones retains 99% of the comparator's accuracy at lower cost.

The Brief

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A short podcast summary of the paper. Written and voiced by AI.

Transcript

JEV-as-a-Judge. Accept When Confident, Escalate When Unsure. By Yubo Li and three others, from Carnegie Mellon University. Published on the twenty-second of September. No code repository is linked to it.

LLM-as-a-judge makes evaluation possible across very different tasks, but at scale two things become critical: what each judgment costs, and whether the judge's confidence can be trusted. The authors ask whether a decision-only judge can serve as a cheap first pass, and also identify when stronger evaluation is needed. Their claim is that it can, and that its own confidence tells you when to escalate.

The judge is jev-as-a-judge. It was compared with sixteen generative and reward-model judges, with blinded human adjudication. On ordinary preference and on evidence-grounded factuality, it comes within three percentage points of a state-of-the-art LLM judge, the strongest comparator, at zero point three six percent of that comparator's fee.

Larger gaps appear when a judgment requires checking a derivation, or resisting a wrong answer that is elaborately written. On several benchmarks, JEV's gap to the comparator is concentrated in its low-confidence decisions. That is what makes a cascade possible. A frozen cascade that accepts confident verdicts and escalates uncertain ones retains ninety-nine percent of the comparator's accuracy at lower cost.

The near-parity holds for ordinary preference and factuality. It does not hold for checking derivations or for resisting elaborate wrong answers. And the concentration of errors in low-confidence decisions is reported on several benchmarks, not all.

The title states the policy in six words: accept when confident, escalate when unsure. Where the cheap judge is sure, it is usually right, and where it is unsure, a stronger judge can take over.

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Learn it by doing: make the calls the authors made, guess the result before you see it, and defend it in a viva graded on your own words. Chapter 1 is right here.

Chapter 1 🧩 · The problem

Good judging is expensive. Here the question is how much of it you really need.

You grade huge numbers of model outputs with a strong reasoning LLM. Every verdict burns reasoning tokens, so fees and latency pile up with each new model revision.

The road ahead

  1. 1 · The problem ~7 min Grading every output with a strong reasoning judge is costly and slow, and a model's own confidence cannot simply be trusted.
  2. 2 · What came before ~3 min
  3. 3 · The key idea ~9 min The cheap judge's errors sit mostly where it is unsure, so its confidence can decide which items need the strong judge.
  4. 4 · Choose your own research ~3 min
  5. 5 · Build the method ~8 min Run the cheap judge on everything, read each verdict's confidence, and pass only the uncertain items to a stronger LLM judge.
  6. 6 · The experiment ~6 min You’ll guess: On ordinary preference and factuality, jev-as-a-judge came close to the strongest LLM judge. What share of that judge's fee did it cost?
  7. 7 · The viva ~5 min Three questions from the examiners, answered in your own words. Win it for the paper’s trophy.
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