Yao Ma
Also known as Ma Yao
As of May 2026, Yao Ma is an applied scientist at Amazon whose work spans reinforcement learning from human feedback and news recommendation. He coauthored a 2024 news-ranking framework that combines pointwise relevance predictions with pairwise comparisons. His graph-routing fine-tuning paper appeared at CoLLAs in 2024 and in PMLR in 2025. In 2026, he coauthored LLMEvalRec for news-recommendation evaluation, ESRRSim for strategic-risk testing, and ARES for repairing joint failures in language and reward models. In May 2026, he explained how human rankings train auxiliary reward models for Amazon's policy-adherent responses.
- Now at
- Amazon
Timeline
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2024
Pointwise-pairwise news ranking
In 2024, he coauthors an efficient framework for language-model news recommendation that combines pointwise relevance predictions with pairwise comparisons. Experiments outperform state-of-the-art methods on the MIND and Adressa datasets.
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2024–2025
Graph routing for fine-tuning
At CoLLAs in 2024, he coauthors a gradual fine-tuning method that represents source domains as a weighted graph and uses graph routing to choose the training order. PMLR publishes it in 2025; its best strategy improves NLI accuracy by 2.3% over state-of-the-art and achieves competitive results on sentiment analysis.
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April 2026
Testing strategic reasoning risks
In April 2026, he coauthors ESRRSim, an agentic framework that tests deception, evaluation gaming, and reward hacking in language models. It groups seven risk categories into 20 subcategories and uses paired rubrics to assess model responses and reasoning traces.
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May 2026
Explaining Amazon's RLHF
In May 2026, he explains how human feedback and preference comparisons guide RLHF, while human-ranked responses train auxiliary reward models for Amazon policy-adherent outputs.
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2026
Simulating news readers
In 2026, he coauthors LLMEvalRec, which uses language-model agents to simulate user behavior for news-recommendation evaluation. Its generated data reaches a 0.97 Spearman correlation with real evaluation rankings, and production validation tracks click-through-rate improvements.
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July 2026
Repairing reward-model failures
In July 2026, he coauthors ARES, which finds cases where the core language model and its reward model fail together. It generates adversarial prompts, fine-tunes the reward model to detect harmful content, and uses the improved model to optimize the core model.
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May 2026
Applied scientist at Amazon
In May 2026, he is an applied scientist at Amazon.
Sources and credits
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- Efficient pointwise-pairwise learning-to-rank for news recommendation
- Gradual Fine-Tuning with Graph Routing for Multi-Source Unsupervised Domain Adaptation
- Gradual fine-tuning with graph routing for multi-source unsupervised domain adaptation
- Emergent Strategic Reasoning Risks in AI: A Taxonomy-Driven Evaluation Framework
- Building trust into AI
- LLMEvalRec: An agentic framework for simulating users to evaluate news recommendation systems
- ARES: Adaptive red-teaming and end-to-end repair of policy-reward system
- ARES: Adaptive Red-Teaming and End-to-End Repair of Policy-Reward System