Toward Autonomous Long-Horizon Engineering for ML Research

Guoxin Chen, Jie Chen, Lei Chen, Zhao Jiale, Fanzhe Meng, Xin Zhao, Ruihua Song, Cheng Chen, Ji-Rong Wen, Kai Jia


Abstract
Agentic systems increasingly automate pieces of AI research. Yet turning underspecified research objectives into runnable, experimentally validated ML systems remains a central bottleneck. We study this operational setting as long-horizon ML research engineering: converting a research specification into a runnable ML system through repeated implementation, experimentation, and refinement. The central challenge is to sustain cumulative project progress across heterogeneous stages under delayed, confounded feedback. We introduce AiScientist, a multi-agent system built around thin control over thick state: a lightweight hierarchical research team coordinates through a File-as-Bus workspace that preserves decision-relevant artifacts across roles and invocations. On PaperBench, AiScientist improves over the strongest matched baselines by 9.92 and 11.15 points with Gemini-3-Flash and GLM-5, respectively. On MLE-Bench Lite, it reaches 81.82 Any Medal% under both backbones, improving over the strongest matched baselines by 4.55 and 16.67 points, and exceeding a Codex/GPT-5.5 xhigh frontier harness reference by 13.64 Any Medal points. Ablations and process analyses show that durable project state is central to later-round refinement: removing File-as-Bus lowers PaperBench score by 6.41 points and MLE-Bench Lite Any Medal% by 31.82 points. These results suggest that long-horizon AI research is not only a problem of stronger local reasoning, but a systems problem of maintaining cumulative, inspectable project progress.
Anthology ID:
2026.findings-emnlp.2200
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
47116–47131
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URL:
https://aclanthology.org/2026.findings-emnlp.2200/
DOI:
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Cite (ACL):
Guoxin Chen, Jie Chen, Lei Chen, Zhao Jiale, Fanzhe Meng, Xin Zhao, Ruihua Song, Cheng Chen, Ji-Rong Wen, and Kai Jia. 2026. Toward Autonomous Long-Horizon Engineering for ML Research. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 47116–47131, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Toward Autonomous Long-Horizon Engineering for ML Research (Chen et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2200.pdf