Min-k Sampling: Decoupling Truncation from Temperature Scaling via Relative Logit Dynamics
Pith reviewed 2026-05-10 16:05 UTC · model grok-4.3
The pith
Min-k sampling detects semantic cliffs in sorted logits to make truncation invariant to temperature.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Min-k Sampling analyzes the local shape of the sorted logit distribution to identify semantic cliffs through a position-weighted relative decay rate. By dynamically setting truncation boundaries at each generation step based on this rate, the method achieves strict temperature invariance while remaining sensitive to fine-grained confidence structure among top candidates.
What carries the argument
Position-weighted relative decay rate computed on the sorted logit distribution, which locates semantic cliffs for per-step dynamic truncation.
If this is right
- Text quality remains high on reasoning benchmarks and creative writing tasks across temperature values.
- Performance stays robust at extreme temperatures where probability-based truncation collapses.
- Hyperparameter choices affect results less than in comparable methods.
- Local logit-shape analysis outperforms global statistics approaches such as Top-n sigma.
Where Pith is reading between the lines
- The same relative-decay logic could be tested on non-transformer generators to check whether semantic cliffs appear in other sequence models.
- If the cliffs prove stable across model scales, Min-k could reduce the need for per-task temperature sweeps in deployment.
- Combining the local decay signal with existing probability-space guards might yield hybrid samplers that inherit invariance while retaining probability normalization.
Load-bearing premise
Sharp transitions from high-confidence core tokens to uncertain long-tail tokens exist in the sorted logit distribution and can be reliably identified by a position-weighted relative decay rate at every generation step.
What would settle it
A generation run in which changing the temperature moves the detected truncation point inconsistently, producing different retained token sets for the same relative decay threshold.
Figures
read the original abstract
The quality of text generated by large language models depends critically on the decoding sampling strategy. While mainstream methods such as Top-$k$, Top-$p$, and Min-$p$ achieve a balance between diversity and accuracy through probability-space truncation, they share an inherent limitation: extreme sensitivity to the temperature parameter. Recent logit-space approaches like Top-$n\sigma$ achieve temperature invariance but rely on global statistics that are susceptible to long-tail noise, failing to capture fine-grained confidence structures among top candidates. We propose \textbf{Min-$k$ Sampling}, a novel dynamic truncation strategy that analyzes the local shape of the sorted logit distribution to identify "semantic cliffs": sharp transitions from high-confidence core tokens to uncertain long-tail tokens. By computing a position-weighted relative decay rate, Min-$k$ dynamically determines truncation boundaries at each generation step. We formally prove that Min-$k$ achieves strict temperature invariance and empirically demonstrate its low sensitivity to hyperparameter choices. Experiments on multiple reasoning benchmarks, creative writing tasks, and human evaluation show that Min-$k$ consistently improves text quality, maintaining robust performance even under extreme temperature settings where probability-based methods collapse. We make our code, models, and analysis tools publicly available.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes Min-k Sampling, a dynamic logit-space truncation method for LLM decoding that detects 'semantic cliffs' (sharp transitions from high-confidence core tokens to uncertain long-tail tokens) in the sorted logit distribution via a position-weighted relative decay rate computed at each step. It claims a formal proof of strict temperature invariance (decoupling truncation from temperature scaling) and reports empirical gains in text quality on reasoning benchmarks, creative writing tasks, and human evaluations, with robustness even at extreme temperatures where Top-k/p and Min-p methods degrade.
Significance. If the temperature-invariance proof is correct and the cliff-detection mechanism reliably identifies semantically meaningful boundaries across models and tasks, Min-k could meaningfully reduce hyperparameter sensitivity in sampling, addressing a practical limitation of probability-space methods. The public release of code, models, and analysis tools is a clear strength that supports reproducibility. However, the result's impact is tempered by the load-bearing assumption that sharp, detectable cliffs exist in typical logit distributions; without broader validation, the method's advantages may be narrower than claimed.
major comments (3)
- [§4] §4 (Formal Proof of Temperature Invariance): The claim of strict invariance rests on the position-weighted relative decay rate being unaffected by uniform logit scaling (1/T). The provided derivation should explicitly show that the detected k remains identical for any T>0, including the normalization or relative-difference steps that achieve this; without the full algebraic steps, it is unclear whether the invariance holds only under additional assumptions on logit linearity.
- [§3.1] §3.1 (Semantic Cliff Identification): The method's truncation boundary is defined by identifying sharp transitions via the position-weighted relative decay rate. This assumption is not guaranteed for smooth or noisy logit distributions (common after high-temperature scaling or in certain model families). The paper should supply either a counterexample analysis or empirical checks on cases where the decay is gradual to confirm that boundary selection remains non-arbitrary and semantically grounded.
- [Experiments] Experiments section / Table 2: The reported robustness under extreme temperatures is central to the practical claim, yet the tables lack per-temperature variance, statistical significance tests against Min-p, and details on how the single hyperparameter of Min-k was chosen or swept. These omissions make it difficult to judge whether the gains are robust or sensitive to implementation choices.
minor comments (3)
- [§2] The abstract and §2 would benefit from a concise comparison table contrasting Min-k with Top-nσ on noise sensitivity and with Min-p on temperature dependence.
- [§3] Notation for the decay-rate formula (Eq. (X)) should explicitly define the position-weighting function and the exact threshold for 'cliff' detection to avoid ambiguity in reproduction.
- A few minor typographical inconsistencies appear in the figure captions and reference list; these do not affect readability but should be cleaned in revision.
Simulated Author's Rebuttal
We thank the referee for their constructive and detailed review of our manuscript. We address each major comment below and will revise the paper to strengthen the presentation of the proof, the analysis of cliff detection, and the experimental reporting.
read point-by-point responses
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Referee: [§4] §4 (Formal Proof of Temperature Invariance): The claim of strict invariance rests on the position-weighted relative decay rate being unaffected by uniform logit scaling (1/T). The provided derivation should explicitly show that the detected k remains identical for any T>0, including the normalization or relative-difference steps that achieve this; without the full algebraic steps, it is unclear whether the invariance holds only under additional assumptions on logit linearity.
Authors: We agree that the proof would benefit from expanded algebraic detail. In the revised manuscript we will include the complete step-by-step derivation in §4. We will explicitly demonstrate that uniform scaling of the logit vector by 1/T leaves both the relative differences (l_i - l_{i+1}) and the position-weighted decay rate unchanged after normalization, so that the argmax over the decay metric (and thus the detected k) is identical for any T > 0. The argument relies only on the definition of relative decay and the fact that scaling preserves order and relative gaps; no linearity assumption on the logits is required. revision: yes
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Referee: [§3.1] §3.1 (Semantic Cliff Identification): The method's truncation boundary is defined by identifying sharp transitions via the position-weighted relative decay rate. This assumption is not guaranteed for smooth or noisy logit distributions (common after high-temperature scaling or in certain model families). The paper should supply either a counterexample analysis or empirical checks on cases where the decay is gradual to confirm that boundary selection remains non-arbitrary and semantically grounded.
Authors: The referee correctly identifies that the method presupposes detectable cliffs. Our existing experiments already cover high-temperature regimes in which logit distributions become smoother, and Min-k continues to outperform baselines. To address the concern directly, we will add an empirical subsection (or appendix) containing visualizations of sorted logit curves and decay-rate profiles across temperatures and model families, together with quantitative checks showing that the selected boundaries still correlate with downstream semantic quality metrics even when the decay is more gradual. revision: yes
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Referee: [Experiments] Experiments section / Table 2: The reported robustness under extreme temperatures is central to the practical claim, yet the tables lack per-temperature variance, statistical significance tests against Min-p, and details on how the single hyperparameter of Min-k was chosen or swept. These omissions make it difficult to judge whether the gains are robust or sensitive to implementation choices.
Authors: We acknowledge these reporting omissions. The revised Experiments section and Table 2 will report per-temperature standard deviations computed over multiple random seeds, include statistical significance tests (paired t-tests or Wilcoxon signed-rank tests) against Min-p and other baselines, and add a paragraph describing the hyperparameter sweep performed for Min-k, the range of values tested, and the validation criterion used to select the final operating point. revision: yes
Circularity Check
No significant circularity; invariance derived from relative logit definition
full rationale
The paper defines Min-k via position-weighted relative decay rate on sorted logits to detect semantic cliffs, then formally proves temperature invariance as a mathematical consequence of that construction. No steps reduce a claimed prediction or result to a fitted parameter or self-citation by construction. The central claim remains independent of its inputs, with the proof presented as following from the relative dynamics rather than tautological renaming or calibration. This yields only minor (non-load-bearing) circularity risk at most.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption The sorted logit distribution at each generation step contains identifiable sharp transitions (semantic cliffs) from high-confidence tokens to uncertain tail tokens.
Reference graph
Works this paper leans on
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[1]
Adaptive contrastive search: Uncertainty- guided decoding for open-ended text generation. In Findings of the Association for Computational Lin- guistics: EMNLP 2024, pages 15060–15080, Miami, Florida, USA. Association for Computational Lin- guistics. Dan Hendrycks, Collin Burns, Saurav Kadavath, Akul Arora, Steven Basart, Eric Tang, Dawn Song, and Jacob S...
work page 2024
-
[2]
Truncation sampling as language model desmoothing. InFindings of the Association for Com- putational Linguistics: EMNLP 2022, pages 3414– 3427, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics. Ari Holtzman, Jan Buys, Li Du, Maxwell Forbes, and Yejin Choi. 2020. The curious case of neural text de- generation. InInternational Conf...
work page 2022
-
[3]
InThe Twelfth In- ternational Conference on Learning Representations (ICLR 2024)
Let’s verify step by step. InThe Twelfth In- ternational Conference on Learning Representations (ICLR 2024). Wang Ling, Dani Yogatama, Chris Dyer, and Phil Blun- som. 2017. Program induction by rationale genera- tion: Learning to solve and explain algebraic word problems. InProceedings of the 55th Annual Meet- ing of the Association for Computational Ling...
work page 2024
-
[4]
Turning up the heat: Min-p sampling for cre- ative and coherent llm outputs. InInternational Con- ference on Learning Representations(ICLR 2025). Qwen Team. 2025. Qwen3 technical report.Preprint, arXiv:2505.09388. David Rein, Betty Li Hou, Asa Cooper Stickland, Jack- son Petty, Richard Yuanzhe Pang, Julien Dirani, Ju- lian Michael, and Samuel R. Bowman. 2...
work page internal anchor Pith review Pith/arXiv arXiv 2025
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Relevance– Does the response ad- dress the prompt appropriately?
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Coherence– Is the response well- organized and logically structured?
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Completeness– Does the response fully answer the question?
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Accuracy– Is the information pro- vided correct?
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[9]
Quality– Is the writing clear, fluent, and human-like? How to Respond In the ‘Your Preference’ column, enter: •A– if Response A is clearly better •B– if Response B is clearly better • Tie– if both responses are roughly equal in quality Important Notes • Read both responses completely before deciding • Focus on overall quality, not just length • Ideally, u...
work page 2058
discussion (0)
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