Tiancheng He
Author directory2026
An Automated Pipeline for Provably Retrieval-Dependent Benchmark Construction over Dynamic Knowledge
Heng Zhou | Ao Yu | Yuchen Fan | Li Kang | Jianing Shi | Yongting Zhang | Yutao Fan | Tiancheng He | Yibing Lin | Hejia Geng | Yuhao Wu | Xiufeng Song | Zhemeng Zhang | Songtao Huang | Yiran Qin | Wenlong Zhang | Lei Bai | Zhenfei Yin
Findings of the Association for Computational Linguistics: EMNLP 2026
Heng Zhou | Ao Yu | Yuchen Fan | Li Kang | Jianing Shi | Yongting Zhang | Yutao Fan | Tiancheng He | Yibing Lin | Hejia Geng | Yuhao Wu | Xiufeng Song | Zhemeng Zhang | Songtao Huang | Yiran Qin | Wenlong Zhang | Lei Bai | Zhenfei Yin
Findings of the Association for Computational Linguistics: EMNLP 2026
Static benchmarks often conflate memorization with reasoning, failing to capture the dynamic nature of world knowledge. We present LiveSearchBench, a scalable pipeline that automatically constructs snapshot-grounded benchmarks from knowledge graph differentials, in which every answer is unique and SPARQL-verifiable against a target snapshot. Unlike prior template-based approaches, our method leverages topology-aware synthesis to generate multi-constraint compositional questions with unique answers guaranteed via SPARQL validation. Evaluating 1,000 questions across three difficulty levels on both open-weight and frontier models, we expose a pronounced Recency Gap on facts that post-date a model’s training cutoff, particularly for compositional queries; retrieval dependence is thus an empirical property we measure, not a formal guarantee we claim. Through Oracle and Wikidata-as-corpus analyses, we disentangle dual failure modes: retrieval coverage limitations for single-hop questions and reasoning failures for compositional queries even with ground-truth evidence. LiveSearchBench provides both a rigorous construction methodology and a continuously updatable testbed for evaluating evidence integration under evolving knowledge.
LatticeMind: A Conflict-Aware Memory Primitive for Multi-Agent Systems
Heng Zhou | Lian Zhang | Yutao Fan | Tiancheng He | Siki Chen | Hejia Geng | Philip Torr | Zhenfei Yin
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Heng Zhou | Lian Zhang | Yutao Fan | Tiancheng He | Siki Chen | Hejia Geng | Philip Torr | Zhenfei Yin
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Multi-agent LLM systems often fail not for lack of candidate answers, but because they have no persistent mechanism for deciding which incompatible claim should currently be trusted. Majority vote, debate, and judge-based selection choose an output without recording which claim wins, which is contested, or why a later update supersedes it. We present LatticeMind, a conflict-aware structured memory that handles contradiction at write time. It maintains explicit item status, applies cheap symbolic conflict checks, and routes the flagged cases to an LLM reconciler. On a label-blind ConflictBank evaluation that removes source-name hints, over a uniform draw of 200 examples from the full benchmark pool, LatticeMind reaches 0.965 accuracy versus 0.525 for the strongest baseline, with every gap significant at p<10-24 by paired McNemar test. Ablations show that removing the checker or the reconciler costs 12 to 14 points. Our claims are scoped to credibility conflicts, where one claim should defeat another: the coordination branch of the design is a safety override that we do not validate empirically, and all prompt-based comparisons are conditioned on a single backbone. On three secondary planning benchmarks and one synthetic scheduling diagnostic the picture is mixed: LatticeMind beats naive merge on three of four, but does not replace deliberation methods on tasks rewarding iterative search.
SaFeR-Steer: Evolving Multi-Turn MLLMs via Synthetic Bootstrapping and Feedback Dynamics
Haolong Hu | Hanyu Li | Tiancheng He | Huahui Yi | An Zhang | Qiankun Li | Kun Wang | Yang Liu | Zhigang Zeng
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Haolong Hu | Hanyu Li | Tiancheng He | Huahui Yi | An Zhang | Qiankun Li | Kun Wang | Yang Liu | Zhigang Zeng
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
MLLMs are increasingly deployed in multi-turn settings, where attackers can escalate unsafe intent through the evolving visual-text history and exploit long-context safety decay. Yet safety alignment is still dominated by single-turn data and fixed-template dialogues, leaving a mismatch between training and deployment.
To bridge this gap, we propose SaFeR-Steer, a progressive multi-turn alignment framework that combines staged synthetic bootstrapping with tutor-in-the-loop GRPO to train a single student under adaptive, on-policy attacks. We also introduce Trajectory-Consistent Summative Reward (TCSR), which aggregates the historical minimum and average of turn rewards so that any low-quality turn affects the trajectory-level return.
I. Dataset. We release STEER, a multi-turn multimodal safety dataset with STEER-SFT (12,934), STEER-RL (2,000), and STEER-Bench (3,227) dialogues spanning 1–10 turns. II. Experiment. Starting from Qwen2.5-VL-3B/7B, SaFeR-Steer substantially improves Safety/Helpfulness on both single-turn (48.30/45.86 → 81.84/70.77 for 3B; 56.21/60.32 → 87.89/77.40 for 7B) and multi-turn benchmarks (12.55/27.13 → 55.58/70.27 for 3B; 24.66/46.48 → 64.89/72.35 for 7B), shifting failures to later turns and yielding robustness beyond scaling alone.
Code is available at https://github.com/Ed-Bg/SaFeR-Steer-full
To bridge this gap, we propose SaFeR-Steer, a progressive multi-turn alignment framework that combines staged synthetic bootstrapping with tutor-in-the-loop GRPO to train a single student under adaptive, on-policy attacks. We also introduce Trajectory-Consistent Summative Reward (TCSR), which aggregates the historical minimum and average of turn rewards so that any low-quality turn affects the trajectory-level return.
I. Dataset. We release STEER, a multi-turn multimodal safety dataset with STEER-SFT (12,934), STEER-RL (2,000), and STEER-Bench (3,227) dialogues spanning 1–10 turns. II. Experiment. Starting from Qwen2.5-VL-3B/7B, SaFeR-Steer substantially improves Safety/Helpfulness on both single-turn (48.30/45.86 → 81.84/70.77 for 3B; 56.21/60.32 → 87.89/77.40 for 7B) and multi-turn benchmarks (12.55/27.13 → 55.58/70.27 for 3B; 24.66/46.48 → 64.89/72.35 for 7B), shifting failures to later turns and yielding robustness beyond scaling alone.
Code is available at https://github.com/Ed-Bg/SaFeR-Steer-full