Rongzhi Zhu

Author directory

2026

Emotional intelligence (EI) in large language models (LLMs) is often evaluated through static understanding tasks or single-response dialogue generation. However, emotion management is interactive. A good response should improve the user’s emotional and relational state over several turns. We introduce EIBench, a simulator-based benchmark for interactive emotion management. EIBench contains 2,222 scenarios, with 2,009 for training and 213 for held-out testing. The scenarios are organized by a 2×2 taxonomy covering Support, Defense, Repair, and Charm. We evaluate 15 open- and closed-source LLMs. Current models perform well on support and rapport-building scenes, but struggle with boundary maintenance under user pressure. To improve the EI ability of LLMs, we propose Centered Turn-Credit GRPO (CTC-GRPO), a GRPO extension that reuses the simulator’s per-turn state updates as dense turn-level feedback while preserving the final outcome reward. CTC-GRPO improves Qwen3-8B from -22.4 to +22.4 on EIBench and also improves on out-of-distribution evaluations including SAGE (+12.4) and EQBench3 (+20.9%). Our results show that simulator-tracked user states can support both evaluation and training for multi-turn emotion management.
Large reasoning models (LRMs) have achieved remarkable success on complex tasks, yet their tendency to "overthink” leads to inefficiencies. Although "save-thinking” prompts are intended to mitigate this issue, we find that LRMs still frequently enter the "Still-thinking” mode instead of the expected "No-thinking” mode, especially when facing difficult queries. First, we examine the LRM’s confidence when terminating thinking process, finding that high perplexity signals internal uncertainty and precedes the thinking process. Second, we analyze the divergence in internal attention distributions across different LRMs. Third, we investigate where the LRM allocates its attention within the prompt, identifying a critical "re-reading” pattern. Based on these analyses, we propose an attention intervention method to regulate this behavior. While this intervention successfully suppresses thinking, we find it causes a drop in accuracy, confirming that the thinking process is functional. Our work provides a mechanistic explanation for this behavior, highlighting the trade-off between instruction following and reasoning correctness, and offers insights for developing more controllable LRMs.
Reinforcement learning (RL) for search agents typically relies on outcome rewards. However, it often fails to achieve effective credit assignment, due to the unclear value of intermediate steps. It is hard to separate their contributions from the final result. In this paper, we propose a dense process supervision method based on fact utility estimation, which models the reasoning process as the accumulation of discrete evidence facts. We first extract structured facts from raw observations and organize them into an explicit fact store. To support credit assignment, we then cluster semantically equivalent facts and infer the posterior utility of each fact cluster using Bayesian estimation over group rollouts. Finally, we convert the estimated fact utilities into dense step-level rewards to guide RL training. Experiments on seven single-hop and multi-hop QA benchmarks show that our method consistently outperforms existing baselines. Ablation studies validate clear relative improvements on multi-hop QA compared to outcome reward-only training.

2025

In this paper, we identify a critical problem, “lost-in-retrieval”, in retrieval-augmented multi-hop question answering (QA): the key entities are missed in LLMs’ sub-question decomposition. “Lost-in-retrieval” significantly degrades the retrieval performance, which disrupts the reasoning chain and leads to the incorrect answers. To resolve this problem, we propose a progressive retrieval and rewriting method, namely ChainRAG, which sequentially handles each sub-question by completing missing key entities and retrieving relevant sentences from a sentence graph for answer generation. Each step in our retrieval and rewriting process builds upon the previous one, creating a seamless chain that leads to accurate retrieval and answers. Finally, all retrieved sentences and sub-question answers are integrated to generate a comprehensive answer to the original question. We evaluate ChainRAG on three multi-hop QA datasets—MuSiQue, 2Wiki, and HotpotQA—using three large language models: GPT4o-mini, Qwen2.5-72B, and GLM-4-Plus. Empirical results demonstrate that ChainRAG consistently outperforms baselines in both effectiveness and efficiency.