REVIEW 3 major objections 4 minor 30 references
State-of-the-art LLMs cannot reliably spot a student's first math error even with the gold solution in hand; a rewritten 'corrected student solution' improves most models.
Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →
Even with the gold solution in hand, large language models locate the first error step in student math solutions poorly; providing a generated corrected student solution improves accuracy.
T0 review reviewed 2026-08-05 challenge →
load-bearing objection Useful empirical study on error localization with corrected student solutions, but the title oversells and the key comparison rests on thin validation of the corrected references. the 3 major comments →
LLMs cannot spot math errors, even when allowed to peek into the solution
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
Core claim
The central claim is that access to a correct answer does not give an LLM the ability to critique an incorrect solution: across six models and two datasets, adding the gold solution to the prompt raises first-error localization only modestly, and exact-match accuracy remains far below each model's accuracy on the underlying math problems. The constructive discovery is that what the model is shown matters more than how well the model can solve the problem. If the supplied reference is first rewritten into a 'corrected student solution'—matching the student's step order, notation, and approach up to the point where the real mistake occurs, and only then diverging—most models locate the first e
What carries the argument
The corrected student solution (S′)—an LLM-generated rewrite of the student's faulty steps that fixes the error while preserving the student's approach, notation, and step structure—is the object that carries the argument. The error is located as the first step at which the student trace S and S′ diverge. A second piece of machinery, Semantic Recall, uses BERTScore recall between the reference and the student solution truncated just before the first error to quantify how well a reference is aligned with the student's reasoning; the paper uses it to explain why corrections help, and it is the top-ranked feature in the classifier that predicts whether a model will localize the error correctly.
Load-bearing premise
The method defines the error as the first divergence between the student trace and an LLM-generated corrected version of that trace, so it assumes the correction is mathematically right and faithful to the student's approach in the steps before the true mistake; when that assumption fails, as it does for one of the tested models, the correction hurts rather than helps.
What would settle it
Take a sample of student solutions from VtG where the corrected student solution has been human-verified as correct and stylistically aligned up to the first error step. If models given these verified corrections locate the exact error no better than models given the gold solution, then alignment is not the operative cause. A simpler check: replace LLM-generated corrections with human-written ones that preserve the student's method; if accuracy does not rise above the gold-solution baseline, the benefit comes from the generated text itself rather than from approach alignment.
If this is right
- If the central claim holds, exact error-step localization remains a distinct meta-reasoning bottleneck: even the best settings reach only about 65% on VtG and 51% on PRM800K, well below the same models' problem-solving accuracy.
- Supplying a corrected student solution—rather than a gold solution—is the intervention that consistently raises exact-match accuracy for most models on both datasets, including the largest general-purpose model tested.
- The gain depends on correction quality: when a model generates an incorrect correction that still forces the final answer to match (Qwen2.5-72B-Math), the corrected-solution condition falls below even the no-gold baseline, so corrections need verification before use.
- Semantic alignment between the reference and the student's reasoning up to the first error is the strongest predictor of successful error localization, while the model's ability to solve the problem is nearly irrelevant—so error-localization performance cannot be read off from math-skill benchmarks.
- Error types bias the predictions: misunderstanding-type errors tend to be located later than they occur, while missing-or-extra-variable errors tend to be located slightly early, so practical tutors should condition on error type.
Where Pith is reading between the lines
- If the alignment principle generalizes, the same corrected-trace comparison should transfer to stepwise reasoning in other domains—code debugging, proofs, or multi-step science calculations—where a corrected trace can be diffed against the original.
- The strong decoupling of problem-solving from error localization suggests that training data which only asks models to produce correct solutions will not build critique ability; an explicit objective that first repairs an erroneous trace and then names the error step is a natural test of that idea.
- A fully automatic version of this method could replace LLM-generated corrections with corrections from a symbolic solver or deterministic step-diffing tool, separating the alignment benefit from the correction generator's reliability and making the first-divergence rule auditable.
- For deployed tutoring systems, the Qwen result is a caution: an unverified LLM correction can push feedback toward the wrong step, so corrections should be checked, or flagged with uncertainty, before being shown as the basis of a hint.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper studies first-error-step localization in stepwise student math solutions using the VtG and PRM800K datasets. It evaluates six LLMs in three settings: no reference solution (w/o-S), dataset-provided gold solution (w-GS), and a proposed two-stage condition (w-Cor) in which the LLM first generates a corrected student solution aligned with the student's approach and then localizes the first error as the first divergence between the student trace and the corrected trace. The authors report that w-GS improves over w/o-S but leaves accuracy low, and that w-Cor yields further gains for most models on both datasets. They also present a feature-importance analysis suggesting that semantic alignment between the reference and the student solution is the most predictive feature, and a chi-square analysis arguing that problem-solving ability is weakly correlated with error-localization ability.
Significance. If the central claim were fully supported, the paper would offer a practical and inexpensive method for improving error localization in tutoring systems, and its evidence that meta-reasoning is distinct from problem-solving ability would be valuable. The study has notable strengths: six diverse models, two complementary datasets, a public code/data release, manual annotation with reported inter-annotator agreement, and a concrete failure analysis for Qwen2.5-72B-Math. The finding that gold references help but are insufficient is credible and likely reproducible. However, the main w-Cor result currently rests on a confounded comparison with w-GS and on an under-validated assumption about the quality of LLM-generated corrected solutions. These issues are fixable but are load-bearing for the paper's headline claim.
major comments (3)
- [§2, §3, Table 1] The w-Cor condition is not a controlled comparison with w-GS. In w-Cor, the model first generates a corrected solution S' = LLMθ(P(G,S)) and then uses Q,S,S' for localization; in w-GS it only sees Q,S,G in a single prompt. Thus w-Cor has an additional LLM call that performs its own reasoning about the problem and the student trace. The reported improvements over w-GS (e.g., +11.8 points for Llama3-70B on VtG, +8.9 for Llama3.1-405B on PRM800K) could be attributable to this extra computation rather than to the alignment property of S'. To support the paper's claim that aligned corrected solutions improve localization, an ablation should hold the number of stages fixed—for example, a w-GS condition with an intermediate 'restate/elaborate the gold solution' step, or a condition where the corrected solution is generated without access to the gold solution. Without such a control, Table 1 doe
- [§C.2, Table 9, Limitations] The w-Cor method assumes the generated correction S' is mathematically correct and aligned with S up to the student's first error. This assumption is validated only on 90 corrections (15 per model). At per-model n=15, a reported 93.3% correctness rate has a wide confidence interval, and the paper's own Qwen2.5-72B-Math result (69.6% correctness) shows the assumption can fail. When it fails, the first-divergence rule points at the wrong step. Since most w-Cor gains over w-GS in Table 1 are between 2 and 9 points, an unmeasured correction-failure rate in that range could erase or reverse the reported effect. The Limitations section explicitly concedes that generated corrections 'may still harbor inconsistencies in their intermediate steps' and that expert-annotated corrections were not used. The manuscript should either validate correctness/alignment on the full evaluation sets (or a subst
- [§4.1, Figure 2] The failure analysis for Qwen2.5-72B-Math exposes a compounding-risk issue: the correction stage and the localization stage use the same model, so errors in S' systematically mislead the subsequent localization. The example in Figure 2 shows the original first error remaining in the corrected solution and later contradictory deductions being introduced. This makes w-Cor's benefit model-dependent in a way the paper does not characterize beyond the 15-sample manual check. Since the proposed method is intended as a general recipe, the authors should report a per-model analysis of correction quality versus localization error, or explicitly discuss the dependency and provide guidance on when w-Cor should not be applied.
minor comments (4)
- [§4.1] The text says Qwen2.5-72B-Math 'drops in both w-GS and w-Cor compared to w/o-S,' but Table 1 shows that on PRM800K w-GS (28.50) is actually higher than w/o-S (21.86). The statement is true for VtG, and for w-Cor on PRM800K, but not for w-GS on PRM800K.
- [Table 11] The Llama3-70B block contains a duplicated 'w-GS' row; one of the rows appears to be intended for a different setting or should be removed.
- [Figure 2] The figure caption labels the model as 'Qwen2.5-Math,' while the text and Table 6 consistently refer to 'Qwen2.5-72B-Math.' Please make the naming consistent.
- [§4.2, §C.1] Semantic Recall for w-Cor is computed against a corrected solution that was itself generated from the student solution, so high recall may be partly by construction. The feature-importance result should be interpreted with this in mind, and a brief caveat in the main text would be appropriate.
Circularity Check
No significant circularity: the w-Cor pipeline generates a corrected student solution without using the first-error label, and the central claim is an empirical benchmark result.
full rationale
The paper's central claim is empirical: adding a corrected student solution (w-Cor) improves first-error-step localization over gold-solution (w-GS) and no-solution (w/o-S) baselines. The target label E (first erroneous step) is not used to construct the corrected solution S': the generation prompt (Figure 9) takes only the problem, the gold solution, and the student solution, and the localization prompt (Figure 8) takes the problem, the student solution, and S'. E is therefore not fed into the pipeline, and no fitted parameter is renamed as a prediction. The only self-citation (Srivatsa and Kochmar, 2024) supplies feature-extraction implementations for the auxiliary Random Forest analysis in Section C.4 and is not load-bearing for the main result. The Limitations section explicitly concedes that LLM-generated corrections 'may still harbor inconsistencies in their intermediate steps' and that only 90 corrections were manually verified; this is a validity/robustness caveat, not a circular reduction, because the method does not define E in terms of S' by construction. No uniqueness theorem or ansatz is imported from the authors' prior work. Thus the derivation chain is self-contained and no circular step is present.
Axiom & Free-Parameter Ledger
axioms (4)
- domain assumption The first-error-step annotations in VtG and PRM800K are accurate and consistent.
- domain assumption The gold solutions in VtG and PRM800K are correct and can serve as a reliable reference.
- domain assumption BERTScore recall is a valid proxy for semantic alignment between student and reference solutions.
- domain assumption The LLM-generated corrected student solution, when used as a reference, has the first error at the first divergence from the student trace.
Cite this review
Pith. "Pith review of LLMs cannot spot math errors, even when allowed to peek into the solution." pith.science (2026). https://pith.science/paper/KEHSTKGY
@misc{pith2026250901395,
author = {Pith},
title = {Pith review of: LLMs cannot spot math errors, even when allowed to peek into the solution},
year = {2026},
howpublished = {\url{https://pith.science/paper/KEHSTKGY}},
note = {Machine review of arXiv:2509.01395}
}
read the original abstract
Large language models (LLMs) demonstrate remarkable performance on math word problems, yet they have been shown to struggle with meta-reasoning tasks such as identifying errors in student solutions. In this work, we investigate the challenge of locating the first error step in stepwise solutions using two error reasoning datasets: VtG and PRM800K. Our experiments show that state-of-the-art LLMs struggle to locate the first error step in student solutions even when given access to the reference solution. To that end, we propose an approach that generates an intermediate corrected student solution, aligning more closely with the original student's solution, which helps improve performance.
Figures
Reference graph
Works this paper leans on
-
[1]
online" 'onlinestring :=
ENTRY address archivePrefix author booktitle chapter edition editor eid eprint eprinttype howpublished institution journal key month note number organization pages publisher school series title type volume year doi pubmed url lastchecked label extra.label sort.label short.list INTEGERS output.state before.all mid.sentence after.sentence after.block STRING...
-
[2]
write newline
" write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 global.max substring 't := if while FUNCTION word.in bbl.in capitalize " " * FUNCT...
-
[3]
Josh Achiam, Steven Adler, Sandhini Agarwal, Lama Ahmad, Ilge Akkaya, Florencia Leoni Aleman, Diogo Almeida, Janko Altenschmidt, Sam Altman, Shyamal Anadkat, et al. 2023. Gpt-4 technical report . arXiv preprint arXiv:2303.08774
Pith/arXiv arXiv 2023
-
[4]
John R. Anderson, C. F. Boyle, Albert T. Corbett, and R. Pelletier. 1990. Cognitive Tutors: Lessons Learned . In Advances in Instructional Psychology, volume 4, pages 179--202. Lawrence Erlbaum Associates, Inc
work page 1990
-
[5]
Carpenter, Elizabeth Fennema, Maria L
Thomas P. Carpenter, Elizabeth Fennema, Maria L. Franke, Linda Levi, and Sandra B. Empson. 1989. Cognition and teaching: The role of content knowledge . In Jane Kilpatrick, William G. Martin, and David Schifter, editors, Teachers’ Knowledge and the Mathematics Classroom, pages 49--84. National Council of Teachers of Mathematics
work page 1989
-
[6]
Karl Cobbe, Vineet Kosaraju, Mohammad Bavarian, Mark Chen, Heewoo Jun, Lukasz Kaiser, Matthias Plappert, Jerry Tworek, Jacob Hilton, Reiichiro Nakano, Christopher Hesse, and John Schulman. 2021. https://arxiv.org/abs/2110.14168 Training Verifiers to Solve Math Word Problems . Preprint, arXiv:2110.14168
Pith/arXiv arXiv 2021
-
[7]
Jacob Cohen. 1988. Statistical Power Analysis for the Behavioral Sciences , 2 edition. Lawrence Erlbaum Associates, Hillsdale, NJ
work page 1988
-
[8]
Nico Daheim, Jakub Macina, Manu Kapur, Iryna Gurevych, and Mrinmaya Sachan. 2024. https://doi.org/10.18653/v1/2024.emnlp-main.478 Stepwise Verification and Remediation of Student Reasoning Errors with Large Language Model Tutors . In Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, pages 8386--8411, Miami, Florida, U...
-
[9]
Cuong Dang, Dung D. Le, and Thai Le. 2024. https://arxiv.org/abs/2402.11469 A Curious Case of Searching for the Correlation between Training Data and Adversarial Robustness of Transformer Textual Models . Preprint, arXiv:2402.11469
work page internal anchor Pith review Pith/arXiv arXiv 2024
-
[11]
Aaron Grattafiori, Abhimanyu Dubey, Abhinav Jauhri, Abhinav Pandey, Abhishek Kadian, Ahmad Al-Dahle, Aiesha Letman, Akhil Mathur, Alan Schelten, Alex Vaughan, Amy Yang, Angela Fan, Anirudh Goyal, Anthony Hartshorn, Aobo Yang, Archi Mitra, Archie Sravankumar, Artem Korenev, Arthur Hinsvark, Arun Rao, Aston Zhang, Aurelien Rodriguez, Austen Gregerson, Ava S...
Pith/arXiv arXiv 2024
-
[12]
John Hattie and Helen Timperley. 2007. The Power of Feedback . Review of Educational Research, 77(1):81--112
work page 2007
-
[13]
Dan Hendrycks, Collin Burns, Saurav Kadavath, Akul Arora, Steven Basart, Eric Tang, Dawn Song, and Jacob Steinhardt. 2021. https://arxiv.org/abs/2103.03874 Measuring Mathematical Problem Solving With the MATH Dataset . Preprint, arXiv:2103.03874
Pith/arXiv arXiv 2021
-
[14]
Qinjin Jia, Jialin Cui, Ruijie Xi, Chengyuan Liu, Parvez Rashid, Ruochi Li, and Edward Gehringer. 2024. On Assessing the Faithfulness of LLM-generated Feedback on Student Assignments . In Proceedings of the 17th International Conference on Educational Data Mining, pages 491--499
work page 2024
-
[15]
J. Peter Kincaid, Robert P. Fishburne, Richard L. Rogers, and Brad S. Chissom. 1975. https://apps.dtic.mil/sti/pdfs/ADA006655.pdf Derivation of New Readability Formulas (Automated Readability Index, Fog Count and Flesch Reading Ease Formula) for Navy Enlisted Personnel . Technical Report Research Branch Report 8-75, Naval Air Station Memphis, Research Bra...
work page 1975
-
[16]
Hang Li, Tianlong Xu, Kaiqi Yang, Yucheng Chu, Yanling Chen, Yichi Song, Qingsong Wen, and Hui Liu. 2024. https://arxiv.org/abs/2412.16838 Ask-Before-Detection: Identifying and Mitigating Conformity Bias in LLM-Powered Error Detector for Math Word Problem Solutions . Preprint, arXiv:2412.16838
Pith/arXiv arXiv 2024
-
[17]
Hunter Lightman, Vineet Kosaraju, Yura Burda, Harri Edwards, Bowen Baker, Teddy Lee, Jan Leike, John Schulman, Ilya Sutskever, and Karl Cobbe. 2023. https://arxiv.org/abs/2305.20050 Let's Verify Step by Step . Preprint, arXiv:2305.20050
Pith/arXiv arXiv 2023
-
[18]
Aixin Liu, Bei Feng, Bing Xue, Bingxuan Wang, Bochao Wu, Chengda Lu, Chenggang Zhao, Chengqi Deng, Chenyu Zhang, Chong Ruan, et al. 2024. Deepseek-v3 technical report . arXiv preprint arXiv:2412.19437
Pith/arXiv arXiv 2024
-
[19]
Jakub Macina, Nico Daheim, Sankalan Chowdhury, Tanmay Sinha, Manu Kapur, Iryna Gurevych, and Mrinmaya Sachan. 2023. https://doi.org/10.18653/v1/2023.findings-emnlp.372 M ath D ial: A Dialogue Tutoring Dataset with Rich Pedagogical Properties Grounded in Math Reasoning Problems . In Findings of the Association for Computational Linguistics: EMNLP 2023, pag...
-
[20]
Francisco Ni \ n o-Rojas, Diana Lancheros-Cuesta, Martha Tatiana Pamela Jim \'e nez-Valderrama, Gelys Mestre, and Sergio G \'o mez. 2024. Systematic Review: Trends in Intelligent Tutoring Systems in Mathematics Teaching and Learning . International Journal of Education in Mathematics, Science and Technology, 12(1):203--229
work page 2024
-
[21]
OpenAI, :, Aaron Hurst, Adam Lerer, Adam P. Goucher, Adam Perelman, Aditya Ramesh, Aidan Clark, AJ Ostrow, Akila Welihinda, Alan Hayes, Alec Radford, Aleksander Mądry, Alex Baker-Whitcomb, Alex Beutel, Alex Borzunov, Alex Carney, Alex Chow, Alex Kirillov, Alex Nichol, Alex Paino, Alex Renzin, Alex Tachard Passos, Alexander Kirillov, Alexi Christakis, Alex...
Pith/arXiv arXiv 2024
-
[22]
Louis M. Rea and Richard A. Parker. 1992. Designing and Conducting Survey Research: A Comprehensive Guide . Jossey--Bass, San Francisco, CA
work page 1992
-
[23]
Sidney Siegel. 1956. Nonparametric Statistics for the Behavioral Sciences . McGraw--Hill, Singapore
work page 1956
-
[24]
Kv Aditya Srivatsa and Ekaterina Kochmar. 2024. https://doi.org/10.18653/v1/2024.findings-naacl.72 What Makes Math Word Problems Challenging for LLM s ? In Findings of the Association for Computational Linguistics: NAACL 2024, pages 1138--1148, Mexico City, Mexico. Association for Computational Linguistics
-
[25]
John Sweller, Jeroen JG van Merri \"e nboer, and Fred Paas. 1998. Cognitive architecture and instructional design . Educational Psychology Review, 10(3):251--296
work page 1998
-
[26]
LearnLM Team, Abhinit Modi, Aditya Srikanth Veerubhotla, Aliya Rysbek, Andrea Huber, Brett Wiltshire, Brian Veprek, Daniel Gillick, Daniel Kasenberg, Derek Ahmed, Irina Jurenka, James Cohan, Jennifer She, Julia Wilkowski, Kaiz Alarakyia, Kevin R. McKee, Lisa Wang, Markus Kunesch, Mike Schaekermann, Miruna Pîslar, Nikhil Joshi, Parsa Mahmoudieh, Paul Jhun,...
Pith/arXiv arXiv 2024
-
[27]
Nandan Thakur, Suleman Kazi, Ge Luo, Jimmy Lin, and Amin Ahmad. 2025. https://aclanthology.org/2025.naacl-long.14/ MIRAGE -Bench: Automatic Multilingual Benchmark Arena for Retrieval-Augmented Generation Systems . In Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language T...
work page 2025
-
[28]
Gladys Tyen, Hassan Mansoor, Victor Carbune, Peter Chen, and Tony Mak. 2024. https://doi.org/10.18653/v1/2024.findings-acl.826 LLM s cannot find reasoning errors, but can correct them given the error location . In Findings of the Association for Computational Linguistics: ACL 2024, pages 13894--13908, Bangkok, Thailand. Association for Computational Linguistics
-
[29]
An Yang, Beichen Zhang, Binyuan Hui, Bofei Gao, Bowen Yu, Chengpeng Li, Dayiheng Liu, Jianhong Tu, Jingren Zhou, Junyang Lin, Keming Lu, Mingfeng Xue, Runji Lin, Tianyu Liu, Xingzhang Ren, and Zhenru Zhang. 2024. https://arxiv.org/abs/2409.12122 Qwen2.5-Math Technical Report: Toward Mathematical Expert Model via Self-Improvement . Preprint, arXiv:2409.12122
Pith/arXiv arXiv 2024
-
[30]
Zhongshen Zeng, Pengguang Chen, Shu Liu, Haiyun Jiang, and Jiaya Jia. 2024. https://arxiv.org/abs/2312.17080 MR-GSM8K: A Meta-Reasoning Benchmark for Large Language Model Evaluation . Preprint, arXiv:2312.17080
Pith/arXiv arXiv 2024
-
[31]
Tianyi Zhang, Varsha Kishore, Felix Wu, Kilian Q. Weinberger, and Yoav Artzi. 2020. https://arxiv.org/abs/1904.09675 BERTScore: Evaluating Text Generation with BERT . Preprint, arXiv:1904.09675
Pith/arXiv arXiv 2020
This paper was first reviewed by deepseek-v4-flash on August 5, 2026.
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