mlsanityData to 7 Oct 2026

Let Me Speak Freely? A Study on the Impact of Format Restrictions on Performance of Large Language Models

arXiv 2408.02442 ↗First posted 5 Aug 2024cs.CLcited by 90

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Cited by 21 in LLM reasoning, but placed by its own abstract, which didn’t fit.

Abstract (arXiv)

Structured generation, the process of producing content in standardized formats like JSON and XML, is widely utilized in real-world applications to extract key output information from large language models (LLMs). This study investigates whether such constraints on generation space impact LLMs abilities, including reasoning and domain knowledge comprehension. Specifically, we evaluate LLMs performance when restricted to adhere to structured formats versus generating free-form responses across various common tasks. Surprisingly, we observe a significant decline in LLMs reasoning abilities under format restrictions. Furthermore, we find that stricter format constraints generally lead to greater performance degradation in reasoning tasks.

Key facts. Cited by 90 papers in the map (data through 7 Oct 2026). Builds on 14 of its 30 references that are in the map. First posted on arXiv 5 Aug 2024.

Builds on

14 of 30 references.

References · 14

  1. 2020Language Models are Few-Shot Learnerscited by 32,199
  2. 2021Training Verifiers to Solve Math Word Problemscited by 9,743
  3. 2022Large Language Models are Zero-Shot Reasonerscited by 4,323
  4. 2021Finetuned Language Models Are Zero-Shot Learnerscited by 3,747
  5. 2023Quantifying Language Models' Sensitivity to Spurious Features in Prompt Design or: How I learned to start worrying about prompt formattingcited by 778
  6. 2021Cross-Task Generalization via Natural Language Crowdsourcing Instructionscited by 696
  7. 2023State of What Art? A Call for Multi-Prompt LLM Evaluationcited by 299
  8. 2024Chain-of-Thought Reasoning Without Promptingcited by 208
  9. 2024The Impact of Reasoning Step Length on Large Language Modelscited by 152
  10. 2022DDXPlus: A New Dataset For Automatic Medical Diagnosiscited by 87
  11. 2024FOFO: A Benchmark to Evaluate LLMs' Format-Following Capabilitycited by 79
  12. 2024Automata-based constraints for language model decodingcited by 49
2 more
  1. 2024StreamBench: Towards Benchmarking Continuous Improvement of Language Agentscited by 44
  2. 2023Exploring Lottery Prompts for Pre-trained Language Modelscited by 5

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Cited by year (2026 to 7 Oct)

Citing papers per year: 2024: 14; 2025: 47; 2026: 29.

90 papers.

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  1. 2024xLAM: A Family of Large Action Models to Empower AI Agent Systemscited by 108
  2. 2024TOMATO: Assessing Visual Temporal Reasoning Capabilities in Multimodal Foundation Modelscited by 71
  3. 2025JSONSchemaBench: A Rigorous Benchmark of Structured Outputs for Language Modelscited by 66
  4. 2025DABstep: Data Agent Benchmark for Multi-step Reasoningcited by 44
  5. 2025Flexible and Efficient Grammar-Constrained Decodingcited by 42
  6. 2025The relationship between reasoning and performance in large language models--o3 (mini) thinks harder, not longercited by 39
  7. 2025Learning to Generate Structured Output with Schema Reinforcement Learningcited by 27
  8. 2024LLMs Are Biased Towards Output Formats! Systematically Evaluating and Mitigating Output Format Bias of LLMscited by 24
  9. 2024Steering Large Language Models between Code Execution and Textual Reasoningcited by 24
  10. 2024StructuredRAG: JSON Response Formatting with Large Language Modelscited by 22
  11. 2024Learning Code Preference via Synthetic Evolutioncited by 19
  12. 2025SLOT: Structuring the Output of Large Language Modelscited by 18
38 more
  1. 2024CoMAT: Chain of Mathematically Annotated Thought Improves Mathematical Reasoningcited by 16
  2. 2025Reasoning Beyond Limits: Advances and Open Problems for LLMscited by 16
  3. 2025Constrained Sampling for Language Models Should Be Easy: An MCMC Perspectivecited by 14
  4. 2025Are Vision-Language Models Safe in the Wild? A Meme-Based Benchmark Studycited by 12
  5. 2025REST: Stress Testing Large Reasoning Models by Asking Multiple Problems at Oncecited by 12
  6. 2025ReliableEval: A Recipe for Stochastic LLM Evaluation via Method of Momentscited by 10
  7. 2025AgentInit: Initializing LLM-based Multi-Agent Systems via Diversity and Expertise Orchestration for Effective and Efficient Collaborationcited by 10
  8. 2024MMMT-IF: A Challenging Multimodal Multi-Turn Instruction Following Benchmarkcited by 8
  9. 2025Survey Response Generation: Generating Closed-Ended Survey Responses In-Silico with Large Language Modelscited by 8
  10. 2026Can Textual Reasoning Improve the Performance of MLLMs on Fine-grained Visual Classification?cited by 8
  11. 2025Self-Training Large Language Models for Tool-Use Without Demonstrationscited by 7
  12. 2025Empowering Healthcare Practitioners with Language Models: Structuring Speech Transcripts in Two Real-World Clinical Applicationscited by 7
  13. 2025ThinkFake: Reasoning in Multimodal Large Language Models for AI-Generated Image Detectioncited by 7
  14. 2024"Oh LLM, I'm Asking Thee, Please Give Me a Decision Tree": Zero-Shot Decision Tree Induction and Embedding with Large Language Modelscited by 6
  15. 2024EF-LLM: Energy Forecasting LLM with AI-assisted Automation, Enhanced Sparse Prediction, Hallucination Detectioncited by 6
  16. 2025LLM-Powered Benchmark Factory: Reliable, Generic, and Efficientcited by 6
  17. 2025Output Length Effect on DeepSeek-R1's Safety in Forced Thinkingcited by 6
  18. 2025STEER-BENCH: A Benchmark for Evaluating the Steerability of Large Language Modelscited by 6
  19. 2025Quantifying the Impact of Structured Output Format on Large Language Models through Causal Inferencecited by 5
  20. 2026From Anatomy to Smells: An Empirical Study of SKILL.md in Agent Skillscited by 5
  21. 2026StateBridge: Training-free Hidden-state Alignment for Latent Communication in LLM Multi-Agent Systemscited by 5
  22. 2024Responsible Retrieval Augmented Generation for Climate Decision Making from Documentscited by 4
  23. 2025OpeNLGauge: An Explainable Metric for NLG Evaluation with Open-Weights LLMscited by 4
  24. 2025Reassessing Large Language Model Boolean Query Generation for Systematic Reviewscited by 4
  25. 2025Live API-Bench: 2500+ Live APIs for Testing Multi-Step Tool Callingcited by 4
  26. 2025Benchmarking and Improving LLM Robustness for Personalized Generationcited by 4
  27. 2025EpidemIQs: Prompt-to-Paper LLM Agents for Epidemic Modeling and Analysiscited by 4
  28. 2024Sketch: A Toolkit for Streamlining LLM Operationscited by 3
  29. 2025Can LLMs Extract Frame-Semantic Arguments?cited by 3
  30. 2025CHORUS: Zero-shot Hierarchical Retrieval and Orchestration for Generating Linear Programming Codecited by 3
  31. 2025Constrained Adaptive Rejection Samplingcited by 3
  32. 2025Querying Databases with Function Callingcited by 2
  33. 2025Conditioning Large Language Models on Legal Systems? Detecting Punishable Hate Speechcited by 2
  34. 2025Leveraging LLMs for Mission Planning in Precision Agriculturecited by 2
  35. 2025AraTable: Benchmarking LLMs' Reasoning and Understanding of Arabic Tabular Datacited by 2
  36. 2025Evaluating Structured Decoding for Text-to-Table Generation: Evidence from Three Datasetscited by 2
  37. 2025SafePassage: High-Fidelity Information Extraction with Black Box LLMscited by 2
  38. 2025DICE: Structured Reasoning in LLMs through SLM-Guided Chain-of-Thought Correctioncited by 2

50 most cited of 90 All 90 (JSON)

Similar, not cited

Close in wording, no citation either way

  1. 2026Capacity, Not Format: Rethinking Structured Reasoning Failures
  2. 2023Evaluating the Deductive Competence of Large Language Models
  3. 2025Format-Adapter: Improving Reasoning Capability of LLMs by Adapting Suitable Format
  4. 2026Thinking Before Constraining: A Unified Decoding Framework for Large Language Models
  5. 2024StrucText-Eval: Evaluating Large Language Model's Reasoning Ability in Structure-Rich Text
  6. 2025Position: On the Methodological Pitfalls of Evaluating Base LLMs for Reasoning
  7. 2025An Empirical Study of LLM Reasoning Ability Under Strict Output Length Constraint
  8. 2025Decoupling Task-Solving and Output Formatting in LLM Generation