Pheng-Ann Heng
Author directory2026
Noisy Test-Time Reinforcement Learning for Code LLMs
Xikai Yang | Hieu Trung Nguyen | Dunyuan Xu | Yuzhi Zhao | Jinpeng Li | Wenao Ma | Pheng-Ann Heng
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Xikai Yang | Hieu Trung Nguyen | Dunyuan Xu | Yuzhi Zhao | Jinpeng Li | Wenao Ma | Pheng-Ann Heng
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) have demonstrated remarkable performance across various code-related tasks. However, unlike carefully curated datasets that are typically high-quality and error-free, real-world user instructions are often vague and error-prone, posing significant challenges to the robustness of code LLMs. Furthermore, robustness-oriented fine-tuning relies on paired clean-noisy samples, which are costly to curate and require sophisticated noisy simulation techniques. To address these challenges, we propose the Noisy Test-time Reinforcement Learning framework (NTRL-Code), which enables robust self-evolution of code LLMs using only unlabeled noisy data during the testing stage. Specifically, NTRL-Code uses conservative self-denoising to obtain a cleaner semantic anchor for target estimation, and employs an abstract-syntax-tree (AST)-based structural aggregation mechanism to estimate a proxy target from multiple candidate programs. The policy is then optimized on the original noisy prompts with a hybrid reward that combines format validity, code similarity, and anti-repetition signals. Extensive experiments on three benchmarks, each incorporating character-level, word-level, and paragraph-level perturbations, demonstrate that NTRL-Code yields robust and consistent improvements, stabilizing the predictions of various base models. Our code is available at https://github.com/Xikai97/NTRL-Code.
2025
SciVerse: Unveiling the Knowledge Comprehension and Visual Reasoning of LMMs on Multi-modal Scientific Problems
Ziyu Guo | Renrui Zhang | Hao Chen | Jialin Gao | Dongzhi Jiang | Jiaze Wang | Pheng-Ann Heng
Findings of the Association for Computational Linguistics: ACL 2025
Ziyu Guo | Renrui Zhang | Hao Chen | Jialin Gao | Dongzhi Jiang | Jiaze Wang | Pheng-Ann Heng
Findings of the Association for Computational Linguistics: ACL 2025
The rapid advancement of Large Multi-modal Models (LMMs) has enabled their application in scientific problem-solving, yet their fine-grained capabilities remain under-explored. In this paper, we introduce SciVerse, a multi-modal scientific evaluation benchmark to thoroughly assess LMMs across 5,735 test instances in five distinct versions. We aim to investigate three key dimensions of LMMs: scientific knowledge comprehension, multi-modal content interpretation, and Chain-of-Thought (CoT) reasoning. To unveil whether LMMs possess sufficient scientific expertise, we first transform each problem into three versions containing different levels of knowledge required for solving, i.e., Knowledge-free, -lite, and -rich. Then, to explore how LMMs interpret multi-modal scientific content, we annotate another two versions, i.e., Vision-rich and -only, marking more question information from texts to diagrams. Comparing the results of different versions, SciVerse systematically examines the professional knowledge stock and visual perception skills of LMMs in scientific domains. In addition, to rigorously assess CoT reasoning, we propose a new scientific CoT evaluation strategy, conducting a step-wise assessment on knowledge and logical errors in model outputs. Our extensive evaluation of different LMMs on SciVerse reveals critical limitations in their scientific proficiency and provides new insights into future developments. Project page: https://sciverse-cuhk.github.io
2024
Unveiling the Generalization Power of Fine-Tuned Large Language Models
Haoran Yang | Yumeng Zhang | Jiaqi Xu | Hongyuan Lu | Pheng-Ann Heng | Wai Lam
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Haoran Yang | Yumeng Zhang | Jiaqi Xu | Hongyuan Lu | Pheng-Ann Heng | Wai Lam
Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
While Large Language Models (LLMs) have demonstrated exceptional multitasking abilities, fine-tuning these models on downstream, domain-specific datasets is often necessary to yield superior performance on test sets compared to their counterparts without fine-tuning. However, the comprehensive effects of fine-tuning on the LLMs’ generalization ability are not fully understood.This paper delves into the differences between original, unmodified LLMs and their fine-tuned variants. Our primary investigation centers on whether fine-tuning affects the generalization ability intrinsic to LLMs. To elaborate on this, we conduct extensive experiments across five distinct language tasks on various datasets.Our main findings reveal that models fine-tuned on generation and classification tasks exhibit dissimilar behaviors in generalizing to different domains and tasks.Intriguingly, we observe that integrating the in-context learning strategy during fine-tuning on generation tasks can enhance the model’s generalization ability.Through this systematic investigation, we aim to contribute valuable insights into the evolving landscape of fine-tuning practices for LLMs.
LoRAExit: Empowering Dynamic Modulation of LLMs in Resource-limited Settings using Low-rank Adapters
Jiacheng Liu | Peng Tang | Xiaofeng Hou | Chao Li | Pheng-Ann Heng
Findings of the Association for Computational Linguistics: EMNLP 2024
Jiacheng Liu | Peng Tang | Xiaofeng Hou | Chao Li | Pheng-Ann Heng
Findings of the Association for Computational Linguistics: EMNLP 2024
Large Language Models (LLMs) have exhibited remarkable performance across various natural language processing tasks. However, deploying LLMs on resource-limited settings remains a challenge. While early-exit techniques offer an effective approach, they often require compromised training methods that result in sub-optimal performance. On the other hand, multi-model methods achieve improved results but suffer from significant inference latency and memory consumption. In this paper, we propose LoRAExit, a novel dynamic inference architecture that leverages low-rank adaptors for efficient deployment of LLMs. LoRAExit decouples the training of multiple exit interfaces, enabling the separate optimization of each exit, thereby fundamentally addressing the performance issues of early-exit networks. Moreover, we introduce a superior-exit guided distillation method that effectively utilizes models of different sizes, thereby further enhancing the performance of early exits. Experimental results demonstrate that LoRAExit significantly improves LLM performance when deployed on resource-limited settings.