ai · 8 min read · Apr 21, 2026

Chain-of-Thought Supervision Eliminates Sample Complexity Growth

New theoretical analysis shows intermediate reasoning steps remove dependence on generation length, while end-to-end learning scales unpredictably with sequence depth.

Source: arxiv/cs.LG · Steve Hanneke, Idan Mehalel, Shay Moran · open original ↗

Chain-of-Thought supervision decouples sample complexity from generation length; end-to-end learning exhibits variable scaling.

  • Autoregressive models learn by iterating a next-token generator T times; final token is the output.
  • End-to-End supervision reveals only final outputs; Chain-of-Thought reveals all intermediate tokens.
  • End-to-End sample complexity can scale anywhere from constant to linear with generation length T.
  • Chain-of-Thought supervision makes sample complexity independent of T entirely.
  • Intermediate reasoning access eliminates the penalty of longer generation chains.
  • Analysis resolves open questions about how generation length affects learnability.
  • New combinatorial tools introduced to characterize this taxonomy of scaling behaviors.
  • Result applies to PAC-learning framework for next-token prediction systems.

Astrobobo tool mapping

  • Knowledge Capture Record the distinction between End-to-End and Chain-of-Thought supervision as a decision framework for your next model training project.
  • Focus Brief Summarize the scaling taxonomy (constant to linear for E2E, constant for CoT) and share with your ML team to inform data labeling strategy.
  • Reading Queue Queue the original Joshi et al. (COLT 2025) paper to understand the PAC-learning framework and baseline bounds.

Frequently asked

  • End-to-End supervision provides only the final output token after a model generates T intermediate tokens. Chain-of-Thought supervision reveals all T intermediate tokens produced during generation. This paper shows that access to intermediate tokens eliminates the penalty of longer generation chains on sample complexity, while end-to-end learning may require more data as chains grow.
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APA
Steve Hanneke, Idan Mehalel, Shay Moran. (2026, April 21). Chain-of-Thought Supervision Eliminates Sample Complexity Growth. Astrobobo Content Engine (rewrite of arxiv/cs.LG). https://astrobobo-content-engine.vercel.app/article/chain-of-thought-supervision-eliminates-sample-complexity-growth-aa1ea6
MLA
Steve Hanneke, Idan Mehalel, Shay Moran. "Chain-of-Thought Supervision Eliminates Sample Complexity Growth." Astrobobo Content Engine, 21 Apr 2026, https://astrobobo-content-engine.vercel.app/article/chain-of-thought-supervision-eliminates-sample-complexity-growth-aa1ea6. Based on "arxiv/cs.LG", https://arxiv.org/abs/2604.12013.
BibTeX
@misc{astrobobo_chain-of-thought-supervision-eliminates-sample-complexity-growth-aa1ea6_2026,
  author       = {Steve Hanneke, Idan Mehalel, Shay Moran},
  title        = {Chain-of-Thought Supervision Eliminates Sample Complexity Growth},
  year         = {2026},
  url          = {https://astrobobo-content-engine.vercel.app/article/chain-of-thought-supervision-eliminates-sample-complexity-growth-aa1ea6},
  note         = {Astrobobo rewrite of arxiv/cs.LG, https://arxiv.org/abs/2604.12013},
}

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