COLING 2025 论文列表

Aspect-based Sentiment Analysis (ABSA) evaluates sentiments toward specific aspects of entities within the text. However, attention mechanisms and neural network models struggle with syntactic constraints. The quadratic complexity of attention mechanisms also limits their adoption for capturing long-range dependencies between aspect and opinion words in ABSA. This complexity can lead to the misinterpretation of irrelevant contextual words, restricting their effectiveness to short-range dependencies. To address the above problem, we present a novel approach to enhance long-range dependencies between aspect and opinion words in ABSA (MambaForGCN). This approach incorporates syntax-based Graph Convolutional Network (SynGCN) and MambaFormer (Mamba-Transformer) modules to encode input with dependency relations and semantic information. The Multihead Attention (MHA) and Selective State Space model (Mamba) blocks in the MambaFormer module serve as channels to enhance the model with short and long-range dependencies between aspect and opinion words. We also introduce the Kolmogorov-Arnold Networks (KANs) gated fusion, an adaptive feature representation system that integrates SynGCN and MambaFormer and captures non-linear, complex dependencies. Experimental results on three benchmark datasets demonstrate MambaForGCN’s effectiveness, outperforming state-of-the-art (SOTA) baseline models.

The increasing integration of multimedia such as videos and graphical abstracts in scientific publications necessitates advanced summarization techniques. This paper introduces Uni-SciSum, a framework for Scientific Multimodal Summarization with Multimodal Output (SMSMO), addressing the challenges of fusing heterogeneous data sources (e.g., text, images, video, audio) and outputting multimodal summary within a unified architecture. Uni-SciSum leverages the power of large language models (LLMs) and extends its capability to cross-modal understanding through BridgeNet, a query-based transformer that fuses diverse modalities into a fixed-length embedding. A two-stage training process, involving modal-to-modal pre-training and cross-modal instruction tuning, aligns different modalities with summaries and optimizes for multimodal summary generation. Experiments on two new SMSMO datasets show Uni-SciSum outperforms uni- and multi-modality methods, advancing LLM applications in the increasingly multimodal realm of scientific communication.

The translation capabilities of neural machine translation (NMT) models based on the encoder-decoder framework are extremely potent. Although Large Language Models (LLMs) have achieved remarkable results in many tasks, they have not reached state-of-the-art performance in NMT. However, traditional NMT still faces significant challenges in areas of document translation such as context consistency, tense, and pronoun resolution, where LLMs inherently possess substantial advantages. Instead of directly using LLMs for translation, employing them for Automatic Post-Editing (APE) to post-edit NMT outputs proves to be a viable option. However, document-level bilingual data is extremely scarce. This paper proposes a method that can effectively leverage the capabilities of LLMs to optimize document translation using only monolingual data. By employing two NMT models in opposite directions (Source-to-Target and Target-to-Source), we generate pseudo-document training data for the training of APE. We have identified and resolved the issue between training and inference mode inconsistency brought about by the pseudo-document training data. The final experimental results demonstrate that by using only document-level monolingual data, we can significantly improve the quality of NMT and greatly enhance issues such as reference and contextual consistency in NMT.

Knowledge distillation (KD) is an effective model compression method that can transfer the internal capabilities of large language models (LLMs) to smaller ones. However, the multi-modal probability distribution predicted by teacher LLMs causes difficulties for student models to learn. In this paper, we first demonstrate the importance of multi-modal distribution alignment with experiments and then highlight the inefficiency of existing KD approaches in learning multi-modal distributions. To address this problem, we propose Ranking Loss based Knowledge Distillation (RLKD), which encourages the consistency of the ranking of peak predictions between the teacher and student models. By incorporating word-level ranking loss, we ensure excellent compatibility with existing distillation objectives while fully leveraging the fine-grained information between different categories in peaks of two predicted distribution. Experimental results demonstrate that our method enables the student model to better learn the multi-modal distributions of the teacher model, leading to a significant performance improvement in various downstream tasks.

Quantum computing is rapidly evolving in both physics and computer science, offering the potential to solve complex problems and accelerate computational processes. The development of quantum chips necessitates understanding the correlations among diverse experimental conditions. Semantic networks built on scientific literature, representing meaningful relationships between concepts, have been used across various domains to identify knowledge gaps and novel concept combinations. Neural network-based approaches have shown promise in link prediction within these networks. This study proposes initializing node features using LLMs to enhance node representations for link prediction tasks in graph neural networks. LLMs can provide rich descriptions, reducing the need for manual feature creation and lowering costs. Our method, evaluated using various link prediction models on a quantum computing semantic network, demonstrated efficacy compared to traditional node embedding techniques.

Despite significant progress in abstractive text summarization aimed at generating fluent and informative outputs, how to ensure the factual consistency of generated summaries remains a crucial and challenging issue. In this study, drawing inspiration from advancements in causal inference, we construct causal graphs to analyze the process of abstractive text summarization methods and identify intrinsic causes of factual inconsistency, specifically language bias and irrelevancy bias, and we propose CoFactSum, a novel framework that mitigates the causal effects of these biases through counterfactual estimation for enhancing the factual consistency of the generated content. CoFactSum provides two counterfactual estimation strategies, including Explicit Counterfactual Masking, which employs a dynamic masking approach, and Implicit Counterfactual Training, which utilizes a discriminative cross-attention mechanism. Besides, we propose a Debiasing Degree Adjustment mechanism to dynamically calibrate the level of debiasing at each decoding step. Extensive experiments conducted on two widely used summarization datasets demonstrate the effectiveness and advantages of the proposed CoFactSum in enhancing the factual consistency of generated summaries, outperforming several baseline methods.

Multiparty dialogue question answering (QA) in machine reading comprehension (MRC) is a challenging task due to its complex information flow interactions and logical QA inference. Existing models typically handle such QA tasks by decoupling dialogue information at both speaker and utterance levels. However, few of them consider the logical inference relations in multiparty dialogue QA, leading to suboptimal QA performance. To address this issue, this paper proposes a memory network with logical inference (LIMN) for extractive QA in multiparty dialogues. LIMN introduces an inference module, which is pretrained by incorporating plain QA articles as external knowledge. It generates logical inference-aware representations from latent space for multiparty dialogues. To further model complex interactions among logical dialogue contexts, questions and key-utterance information, a key-utterance-based interaction method is proposed for leverage. Moreover, a multitask learning strategy is adopted for robust MRC. Extensive experiments were conducted on Molweni and FriendsQA benchmarks, which included 25k and 10k questions, respectively. Comparative results showed that LIMN achieves state-of-the-art results on both benchmarks, demonstrating the enhancement of logical QA inference in multiparty dialogue QA tasks.

Event Causality Identification (ECI) aims to identify fine-grained causal relationships between events in an unstructured text. Existing ECI methods primarily rely on knowledge enhanced and graph-based reasoning approaches, but they often overlook the dependencies between similar events. Additionally, the connection between unstructured text and structured knowledge is relatively weak. Therefore, this paper proposes an ECI method enhanced by LLM Knowledge and Concept-Level Event Relations (LKCER). Specifically, LKCER constructs a conceptual-level heterogeneous event graph by leveraging the local contextual information of related event mentions, generating a more comprehensive global semantic representation of event concepts. At the same time, the knowledge generated by COMET is filtered and enriched using LLM, strengthening the associations between event pairs and knowledge. Finally, the joint event conceptual representation and knowledge-enhanced event representation are used to uncover potential causal relationships between events. The experimental results show that our method outperforms previous state-of-the-art methods on both benchmarks, EventStoryLine and Causal-TimeBank.

With the growing need for accessible emotional support, conversational agents are being used more frequently to provide empathetic and meaningful interactions. However, many existing dialogue models struggle to interpret user context accurately due to irrelevant or misclassified knowledge, limiting their effectiveness in real-world scenarios. To address this, we propose a new framework that dynamically filters relevant commonsense knowledge and extracts personalized information to improve empathetic dialogue generation. We evaluate our framework on the ESConv dataset using extensive automatic and human experiments. The results show that our approach outperforms other models in metrics, demonstrating better coherence, emotional understanding, and response relevance.

We explore the use of discourse parsers for extracting a particular discourse structure in a real-world social media scenario. Specifically, we focus on enhancing parser performance through the integration of synthetic data generated by large language models (LLMs). We conduct experiments using a newly developed dataset of 1,170 local RST discourse structures, including 900 synthetic and 270 gold examples, covering three social media platforms: online news comments sections, a discussion forum (Reddit), and a social media messaging platform (Twitter). Our primary goal is to assess the impact of LLM-generated synthetic training data on parser performance in a raw text setting without pre-identified discourse units. While both top-down and bottom-up RST architectures greatly benefit from synthetic data, challenges remain in classifying evaluative discourse structures.

This study introduces KriRAG, a novel Retrieval-Augmented Generation (RAG) architecture designed to assist criminal investigators in analyzing information and overcoming the challenge of information overload. KriRAG structures and summarizes extensive document collections based on existing investigative queries, providing relevant document references and detailed answers for each query. Working with unstructured data from two homicide case files comprising approximately 3,700 documents and 13,000 pages, a comprehensive evaluation methodology is established, incorporating semantic retrieval, scoring, reasoning, and query response accuracy. The system’s outputs are evaluated against queries and answers provided by criminal investigators, demonstrating promising performance with 97.5% accuracy in relevance assessment and 77.5% accuracy for query responses. These findings provide a rigorous foundation for other query-oriented and open-ended retrieval applications. KriRAG is designed to run offline on limited hardware, ensuring sensitive data handling and on-device availability.

This study introduces a character-level approach specifically designed for Arabic NLP tasks, offering a novel and highly effective solution to the unique challenges inherent in Arabic language processing. It presents a thorough comparative study of various character-level models, including Convolutional Neural Networks (CNNs), pre-trained transformers (CANINE), and Bidirectional Long Short-Term Memory networks (BiLSTMs), assessing their performance and exploring the impact of different data augmentation techniques on enhancing their effectiveness. Additionally, it introduces two innovative Arabic-specific data augmentation methods—vowel deletion and style transfer—and rigorously evaluates their effectiveness. The proposed approach was evaluated on Arabic privacy policy classification task as a case study, demonstrating significant improvements in model performance, reporting a micro-averaged F1-score of 93.8%, surpassing state-of-the-art models.

Text style transfer is a challenging research task which modifies the linguistic style of a given text to meet pre-set objectives such as making the text simpler or more accessible. Though large language models have been found to give promising results, text rewriting to improve audience engagement of social media content is vastly unexplored. Our research investigates the performance of various prompting strategies in the task of rewriting Dutch news tweets in specific linguistic styles (formal, casual and factual). Apart from zero-shot and few-shot prompting variants, with and without personas, we also explore prompting with feedback on predicted engagement. We perform an extensive analysis of 18 different combinations of Large Language Models (GPT-3.5, GPT-4, Mistral-7B) and prompting strategies on three different metrics: ROUGE-L, semantic similarity and predicted engagement. We find that GPT-4 with feedback and persona prompting performs the best in terms of predicted engagement for all three language styles. Our results motivate further application of usage of prompting techniques to rewrite news headlines on Twitter to align with specific style guidelines.

Previous benchmarks for evaluating large language models (LLMs) have primarily emphasized quantitative metrics, such as data volume. However, this focus may neglect key qualitative data attributes that can significantly impact the final rankings of LLMs, resulting in unreliable leaderboards. In this paper, we investigate whether current LLM benchmarks adequately consider these data attributes. We specifically examine three attributes: diversity, redundancy, and difficulty. To explore these attributes, we propose a framework with three separate modules, each designed to assess one of the attributes. Using a method that progressively incorporates these attributes, we analyze their influence on the benchmark. Our experimental results reveal a meaningful correlation between LLM rankings on the revised benchmark and the original benchmark when these attributes are accounted for. These findings indicate that existing benchmarks often fail to meet all three criteria, highlighting a lack of consideration for multifaceted data attributes in current evaluation datasets.

This study investigates the effectiveness of Large Language Models (LLMs) for zero-shot keyphrase extraction (KE). We propose and evaluate four prompting strategies: vanilla, role prompting, candidate-based prompting, and hybrid prompting. Experiments conducted on six widely-used KE benchmark datasets demonstrate that Llama3-8B-Instruct with vanilla prompting outperforms state-of-the-art unsupervised methods, PromptRank, by an average of 9.43%, 7.68%, and 4.82% in F1@5, F1@10, and F1@15, respectively. Hybrid prompting, which combines the strengths of vanilla and candidate-based prompting, further enhances overall performance. Moreover role prompting, which assigns a task-related role to LLMs, consistently improves performance across various prompting strategies. We also explore the impact of model size and different LLM series: GPT-4o, Gemma2, and Qwen2. Results show that Llama3 and Gemma2 demonstrate the strongest zero-shot KE performance, with hybrid prompting consistently enhancing results across most LLMs. We hope this study provides insights to researchers exploring LLMs in KE tasks, as well as practical guidance for model selection in real-world applications. Our code is available at https://github.com/kangnlp/Zero-shot-KPE-with-LLMs.

Retrieval-augmented large language models (LLMs) have been remarkably competent in various NLP tasks. However, it was observed by previous works that retrieval is not always helpful, especially when the LLM is already knowledgable on the query to answer. Motivated by this, Adaptive Retrieval-Augmented Generation (ARAG) studies retrieving only when the knowledge asked by the query is absent in the LLM. Previous works of ARAG either require accessing the pre-training corpus or prompting with additional model inferences. Aiming to avoid such drawbacks, we propose to determine whether the model is knowledgeable on a query via inspecting the (contextualized) pre-trained token embeddings of LLMs. We hypothesize that such embeddings capture rich information on the model’s intrinsic knowledge base, which enables an efficient way of judging the necessity to retrieve from an external corpus. Extensive experiments demonstrate our ARAG approach’s superior performance across various benchmarks.

This paper analyzes how writing style affects the dispersion of embedding vectors across multiple, state-of-the-art language models. While early transformer models primarily aligned with topic modeling, this study examines the role of writing style in shaping embedding spaces. Using a literary corpus that alternates between topics and styles, we compare the sensitivity of language models across French and English. By analyzing the particular impact of style on embedding dispersion, we aim to better understand how language models process stylistic information, contributing to their overall interpretability.

Tokenizers act as a bridge between human language and the latent space of language models, influencing how language is represented in these models. Despite the dominance of English-Centric (EC) Large Language Models (LLMs), tokenization methods often fail to fairly represent complex scripts like Tamil, Sinhala, and Hindi, primarily due to pre-tokenization choices. This study demonstrates that pre-tokenization has a more significant impact than tokenization algorithms on achieving egalitarian representation. To address this, we introduce an improvement to the Byte Pair Encoding (BPE) algorithm by incorporating graphemes, which we term Grapheme Pair Encoding (GPE). Our experiments show that grapheme-based character extraction outperforms byte-level tokenizers for complex scripts. We validate this approach through experiments on Tamil, Sinhala, and Hindi. The codebase and resources used in this work are publicly available at https://github.com/vmenan/tokenizers-coling2025.

The increasing size of large language models (LLMs) poses significant challenges due to their high computational costs and energy consumption, making their deployment in industrial settings difficult. Small language models (SLMs) have been introduced to mitigate these challenges by reducing model size while preserving performance. However, the embedding layer, which occupies a significant portion of the model, remains a bottleneck in model compression efforts. In this paper, we valdated vocabulary reduction as a solution to compress the embedding layer and reduce model size without significant loss of performance. We conduct a series of experiments to investigate how vocabulary reduction affects GPU memory footprint, inference speed, and task performance. Our results show that while performance generally declines with vocabulary reduction, fine-tuning can recover much of the lost performance. Moreover, in some tasks, such as truthfulness and summarization, the vocabulary-reduced models outperform the baseline. Finally, we demonstrate that vocabulary reduction can be effectively applied in domain adaptation, particularly in the medical domain, and in multilingual adaptation, improving task efficiency and cross-lingual robustness.