Lei Wang
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2026
VRR: Verification-Guided Retrieval Revision for Multi-Step QA
Zhijie Li | Lei Wang | Tianyuan Li | Bangju Han | Ahtamjan Ahmat | Rui Dong | Zhen Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Zhijie Li | Lei Wang | Tianyuan Li | Bangju Han | Ahtamjan Ahmat | Rui Dong | Zhen Wang
Findings of the Association for Computational Linguistics: EMNLP 2026
Retrieval-augmented language models improve knowledge-intensive question answering, but they remain brittle on multi-step questions, where an early retrieval error can steer subsequent reasoning toward the wrong entity or relation. Existing methods can often detect that the current answer or evidence is unreliable, yet they rarely turn this diagnosis into an explicit retrieval correction. We propose Verification-Guided Retrieval Revision (VRR), a framework that uses verification as a control signal for multi-step retrieval. VRR couples a Generator that proposes search and answers, a Judge that verifies answer correctness and evidential support while emitting structured failure diagnoses, and a Retrieval Context Manager (RCM) that converts these diagnoses into retriever-facing updates such as clue selection, query rewriting, and state-aware evidence ranking. To make this loop learnable, we train VRR in three stages: iterative cold-start training to stabilize search, judge-shaped policy optimization to improve long-horizon reasoning, and diagnosis-conditioned RCM training for retrieval adaptation. Across seven open-domain QA benchmarks with a fixed retriever and corpus, training on HotpotQA and transferring to out-of-domain datasets, VRR surpasses the strongest prior baseline by 4.2 EM on average under budget-aligned evaluation, with larger gains on multi-hop benchmarks (+5.4).
Benchmarking the Fine-Grained Discriminability in Image-Text Retrieval via Controlled Contrastive Differences
Zhen Wang | Xi Zhou | Yating Yang | Bo Ma | Lei Wang | Rui Dong | Azmat Anwar | Siru Miao
Findings of the Association for Computational Linguistics: ACL 2026
Zhen Wang | Xi Zhou | Yating Yang | Bo Ma | Lei Wang | Rui Dong | Azmat Anwar | Siru Miao
Findings of the Association for Computational Linguistics: ACL 2026
Existing cross-modal image-text retrieval models often retrieve samples with inconsistent details. To evaluate fine-grained discriminability, we introduce MSCOCO-CCD and Flickr30k-CCD, with three key features: (1) a two-level image content taxonomy for contrastive sample generation and fine-grained evaluation; (2) annotation of numerous contrastive samples, where each sample differs from the anchor by a controlled contrastive difference (CCD), with the specific type of difference labeled; (3) a fine-grained contrastive discrimination metric to assess the ability to distinguish fine-grained nuances. Extensive experiments demonstrate that contrastive samples can significantly degrade retrieval performance. Furthermore, fine-grained evaluation reveals that current models still struggle to effectively produce discriminative representations on certain feature types, such as entity emotion and scene attribute. Our datasets and related codes will be publicly released.
Not All Queries Are Equal: Query-Type-Aware Mixture-of-Experts for Temporal Knowledge Graph Forecasting
Rong Ma | Bo Ma | Yating Yang | Xi Zhou | Lei Wang | Rui Dong | Ahtamjan Ahmat | Zhen Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Rong Ma | Bo Ma | Yating Yang | Xi Zhou | Lei Wang | Rui Dong | Ahtamjan Ahmat | Zhen Wang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Temporal knowledge graph forecasting predicts future facts from historical snapshots, and its accuracy hinges on how well a model exploits the historical evidence available to each query. Existing methods route every query through a single reasoning pipeline, yet queries with the same predicate form can rest on very different histories and call for different inductive biases. We observe that query histories fall into three regimes: sparse histories with few prior events, recurrent histories dominated by stable repetition, and ambiguous histories with many competing candidates. Building on this observation, we propose QTI-MoE, a Query-Type-aware Inductive-bias Mixture-of-Experts framework. QTI-MoE characterises each query with a soft type label derived from its historical prefix and forwards it to one of three experts whose memory pathways carry complementary biases: recency-weighted aggregation for sparse queries, count-based repetition for recurrent queries, and diversity-normalised scoring for ambiguous queries. QTI-MoE achieves state-of-the-art performance on four standard benchmarks, and a type-stratified analysis confirms that each expert peaks on its target regime.
2025
Beyond Inherent Cognition Biases in LLM-Based Event Forecasting: A Multi-Cognition Agentic Framework
Zhen Wang | Xi Zhou | Yating Yang | Bo Ma | Lei Wang | Rui Dong | Azmat Anwar
Findings of the Association for Computational Linguistics: EMNLP 2025
Zhen Wang | Xi Zhou | Yating Yang | Bo Ma | Lei Wang | Rui Dong | Azmat Anwar
Findings of the Association for Computational Linguistics: EMNLP 2025
Large Language Models (LLMs) exhibit strong reasoning capabilities and are widely applied in event forecasting. However, studies have demonstrated that LLMs exhibit human-like cognitive biases, systematic patterns of deviation from rationality in decision-making. To explore the cognitive biases in event forecasting, we introduce CogForecast, a human-curated dataset comprising six topics. Experimental results on three LLMs reveal significant cognitive biases in LLM-based event forecasting methods. To address this issue, we propose MCA, a Multi-Cognition Agentic framework. Specifically, MCA leverages LLMs to act as multi-cognition event participants, performing perspective-taking based on the cognitive patterns of event participants to alleviate the inherent cognitive biases in LLMs and offer diverse analytical perspectives. Then, MCA clusters agents according to their predictions and derives a final answer through a group-level reliability scoring method. Experimental results on a dataset including eight event categories demonstrate the effectiveness of MCA. Using Llama-3.1-70B, MCA achieves an accuracy of 82.3% (79.5% for the human crowd). Additionally, we demonstrate that MCA can alleviate the cognitive biases in LLMs and investigate three influencing factors.
Mining the Past with Dual Criteria: Integrating Three types of Historical Information for Context-aware Event Forecasting
Rong Ma | Lei Wang | Yating Yang | Bo Ma | Rui Dong | Fengyi Yang | Ahtamjan Ahmat | Kaiwen Lu | Xinyue Wang
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Rong Ma | Lei Wang | Yating Yang | Bo Ma | Rui Dong | Fengyi Yang | Ahtamjan Ahmat | Kaiwen Lu | Xinyue Wang
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Event forecasting requires modeling historical event data to predict future events, and achieving accurate predictions depends on effectively capturing the relevant historical information that aids forecasting. Most existing methods focus on entities and structural dependencies to capture historical clues but often overlook implicitly relevant information. This limitation arises from overlooking event semantics and deeper factual associations that are not explicitly connected in the graph structure but are nonetheless critical for accurate forecasting. To address this, we propose a dual-criteria constraint strategy that leverages event semantics for relevance modeling and incorporates a self-supervised semantic filter based on factual event associations to capture implicitly relevant historical information. Building on this strategy, our method, termed ITHI (Integrating Three types of Historical Information), combines sequential event information, periodically repeated event information, and relevant historical information to achieve context-aware event forecasting. We evaluated the proposed ITHI method on three public benchmark datasets, achieving state-of-the-art performance and significantly outperforming existing approaches. Additionally, we validated its effectiveness on two structured temporal knowledge graph forecasting dataset.
2022
ASCM: An Answer Space Clustered Prompting Method without Answer Engineering
Zhen Wang | Yating Yang | Zhou Xi | Bo Ma | Lei Wang | Rui Dong | Azmat Anwar
Findings of the Association for Computational Linguistics: ACL 2022
Zhen Wang | Yating Yang | Zhou Xi | Bo Ma | Lei Wang | Rui Dong | Azmat Anwar
Findings of the Association for Computational Linguistics: ACL 2022
Prompt-based learning, which exploits knowledge from pre-trained language models by providing textual prompts and designing appropriate answer-category mapping methods, has achieved impressive successes on few-shot text classification and natural language inference (NLI). Because of the diverse linguistic expression, there exist many answer tokens for the same category. However, both manual answer design and automatic answer search constrain answer space and therefore hardly achieve ideal performance. To address this issue, we propose an answer space clustered prompting model (ASCM) together with a synonym initialization method (SI) which automatically categorizes all answer tokens in a semantic-clustered embedding space. We also propose a stable semi-supervised method named stair learning (SL) that orderly distills knowledge from better models to weaker models. Extensive experiments demonstrate that our ASCM+SL significantly outperforms existing state-of-the-art techniques in few-shot settings.