Computation and Language · Cross-listed from cs.IR
What Drives Cross-lingual Ranking? Retrieval Approaches with Multilingual Language Models
Roksana Goworek, Olivia Macmillan-Scott and Eda B. Özyiğit
Cross-lingual information
retrieval (CLIR) enables access to
multilingual knowledge but remains challenging due to disparities in resources, scripts, and weak cross-lingual semantic
alignment in
embedding models. Existing pipelines often rely on translation and monolingual
retrieval heuristics, which add computational overhead and noise, degrading performance. This work systematically evaluates four intervention types, namely document translation,
multilingual dense
retrieval with pretrained encoders, contrastive learning at word, phrase, and query-document levels, and cross-encoder re-ranking, across three
benchmark datasets. We find that dense
retrieval models trained specifically for CLIR consistently outperform lexical matching methods and derive little benefit from document translation. Contrastive learning mitigates
language biases and yields substantial improvements for encoders with weak initial
alignment, and re-ranking can be effective, but depends on the quality of the cross-encoder training data. Although high-resource
languages still dominate overall performance, gains over lexical and document-translated baselines are most pronounced for low-resource and cross-script pairs. These findings indicate that cross-lingual search systems should prioritise semantic
multilingual embeddings and targeted learning-based
alignment over translation-based pipelines, particularly for cross-script and under-resourced
languages.
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Computation and Language
MultiBanAbs: A Comprehensive Multi-Domain Bangla Abstractive Text Summarization Dataset
Md. Tanzim Ferdous, Naeem Ahsan Chowdhury and Prithwiraj Bhattacharjee
This study developed a new Bangla abstractive summarization
dataset to generate concise summaries of Bangla articles from diverse sources. Most existing studies in this field have concentrated on news articles, where journalists usually follow a fixed writing style. While such approaches are effective in limited contexts, they often fail to adapt to the varied nature of real-world Bangla texts. In today's digital era, a massive amount of Bangla content is continuously produced across blogs, newspapers, and social media. This creates a pressing need for summarization systems that can reduce information overload and help readers understand content more quickly. To address this challenge, we developed a
dataset of over 54,000 Bangla articles and summaries collected from multiple sources, including blogs such as Cinegolpo and newspapers such as Samakal and The Business Standard. Unlike single-domain resources, our
dataset spans multiple domains and writing styles. It offers greater adaptability and practical relevance. To establish strong baselines, we trained and evaluated this
dataset using several deep learning and transfer learning models, including LSTM, BanglaT5-small, and MTS-small. The results highlight its potential as a
benchmark for future research in Bangla natural
language processing. This
dataset provides a solid foundation for building robust summarization systems and helps expand NLP resources for low-resource
languages.
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Computation and Language · Cross-listed from cs.AI
PRInTS: Reward Modeling for Long-Horizon Information Seeking
Jaewoo Lee, Archiki Prasad, Justin Chih-Yao Chen et al. (+3 more)
Information-seeking is a core capability for AI
agents, requiring them to gather and reason over tool-generated information across long trajectories. However, such multi-step information-seeking tasks remain challenging for
agents backed by
language models. While process reward models (PRMs) can guide
agents by ranking candidate steps at test-time, existing PRMs - designed for short
reasoning with binary judgment - cannot capture richer dimensions of information-seeking steps, such as tool interactions and
reasoning over tool outputs, nor handle the rapidly growing context in long-horizon tasks. To address these limitations, we introduce PRInTS, a generative PRM trained with dual capabilities: (1) dense scoring based on the PRM's
reasoning across multiple dimensions of step quality (e.g., interpretation of tool outputs, tool call informativeness) and (2) trajectory summarization that compresses the growing context while preserving essential information for step evaluation. Extensive evaluations across FRAMES,
GAIA (levels 1-3), and WebWalkerQA (easy-hard)
benchmarks on multiple models reveal that best-of-n sampling with PRInTS enhances information-seeking in open-source models as well as specialized
agents, matching or surpassing frontier models with a much smaller backbone
agent and outperforming other strong reward modeling baselines.
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All authors Jaewoo Lee, Archiki Prasad, Justin Chih-Yao Chen, Zaid Khan, Elias Stengel-Eskin, Mohit Bansal
Computation and Language · Cross-listed from cs.AI
AutoEnv: Automated Environments for Measuring Cross-Environment Agent Learning
Jiayi Zhang, Yiran Peng, Fanqi Kong et al. (+12 more)
Humans naturally adapt to diverse environments by learning underlying rules across worlds with different dynamics, observations, and reward structures. In contrast, existing
agents typically demonstrate improvements via self-evolving within a single domain, implicitly assuming a fixed environment distribution. Cross-environment learning has remained largely unmeasured: there is no standard collection of controllable, heterogeneous environments, nor a unified way to represent how
agents learn. We address these gaps in two steps. First, we propose AutoEnv, an automated framework that treats environments as factorizable distributions over transitions, observations, and rewards, enabling low-cost (4.12 USD on average) generation of heterogeneous worlds. Using AutoEnv, we construct AutoEnv-36, a
dataset of 36 environments with 358 validated levels, on which seven
language models achieve 12-49% normalized reward, demonstrating the challenge of AutoEnv-36. Second, we formalize
agent learning as a component-centric process driven by three stages of Selection, Optimization, and Evaluation applied to an improvable
agent component. Using this formulation, we design eight learning methods and evaluate them on AutoEnv-36. Empirically, the gain of any single learning method quickly decrease as the number of environments increases, revealing that fixed learning methods do not scale across heterogeneous environments. Environment-adaptive selection of learning methods substantially improves performance but exhibits diminishing returns as the method space expands. These results highlight both the necessity and the current limitations of
agent learning for scalable cross-environment generalization, and position AutoEnv and AutoEnv-36 as a testbed for studying cross-environment
agent learning. The code is avaiable at https://github.com/FoundationAgents/AutoEnv.
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All authors Jiayi Zhang, Yiran Peng, Fanqi Kong, Cheng Yang, Yifan Wu, Zhaoyang Yu, Jinyu Xiang, Jianhao Ruan, Jinlin Wang, Maojia Song, HongZhang Liu, Xiangru Tang, Bang Liu, Chenglin Wu, Yuyu Luo
Computation and Language · Cross-listed from cs.LG
MapFormer: Self-Supervised Learning of Cognitive Maps with Input-Dependent Positional Embeddings
Victor Rambaud, Salvador Mascarenhas and Yair Lakretz
A cognitive map is an internal model which encodes the abstract relationships among entities in the world, giving humans and animals the flexibility to adapt to new situations, with a strong out-of-distribution (OOD) generalization that current AI systems still do not possess. To bridge this gap, we introduce $\textit{MapFormers}$, new
Transformer-based architectures, which can learn cognitive maps from observational data and perform path-integration without supervision. Cognitive maps are learned in the model by disentangling structural relationships in the inputs from their specific content, a property that can be achieved by updating position encodings with input-dependent
matrices, built as exponentials of learned combinations of Lie-
algebra generators. We developed two variants of $\textit{MapFormers}$ that unify absolute and relative positional encoding to model episodic (EM) and working
memory (WM), respectively. We tested $\textit{MapFormers}$ on several formal tasks targeting distinct cognitive capacities, including gating, 2D
navigation and nested hierarchies (Dyck
Languages). Our results demonstrate that $\textit{MapFormers}$ significantly outperform current AI architectures, achieving near-perfect OOD generalization where standard models fail. Furthermore, we show that $\textit{MapFormers}$ are scalable; evaluations on naturalistic data yield perplexity improvements over baselines, suggesting that these principles extend to large-scale, real-world domains. These results are obtained through efficient parallel computation on commutative maps, though our models can also learn non-commutative cognitive maps via sequential path-integration. Overall, these results suggest that input-dependent
matrices provide a critical structural bias, by disentangling abstract relations from content in order to drive robust OOD generalization.
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Computation and Language · Cross-listed from cs.LG
CDLM: Consistency Diffusion Language Models For Faster Sampling
Minseo Kim, Chenfeng Xu, Coleman Hooper et al. (+5 more)
Diffusion Language Models (DLMs) offer a promising parallel generation paradigm but suffer from slow inference due to numerous refinement steps and the inability to use standard KV caching. We introduce CDLM (Consistency
Diffusion Language Models), a training-based acceleration method that simultaneously tackles both bottlenecks. CDLM integrates consistency modeling to drastically reduce the number of required sampling steps by enabling multi-
token finalization. Furthermore, we enforce a block-wise causal
attention mask during fine-tuning, making the model fully compatible with KV caching. Experiments show CDLM achieves 3.6x-14.5x lower latency while maintaining competitive accuracy on math and coding tasks. The full training and evaluation code is available at https://github.com/SqueezeAILab/CDLM.
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All authors Minseo Kim, Chenfeng Xu, Coleman Hooper, Harman Singh, Ben Athiwaratkun, Ce Zhang, Kurt Keutzer, Amir Gholami
Computation and Language · Cross-listed from cs.LG
Wrist Photoplethysmography Predicts Dietary Information
Kyle Verrier, Achille Nazaret, Joseph Futoma et al. (+2 more)
Whether wearable photoplethysmography (PPG) contains dietary information remains unknown. We trained a
language model on 1.1M meals to predict meal descriptions from PPG, aligning PPG to text. PPG nontrivially predicts meal content; predictability decreases for PPGs farther from meals. This transfers to dietary tasks: PPG increases AUC by 11% for intake and satiety across held-out and independent cohorts, with gains robust to text degradation. Wearable PPG may enable passive dietary monitoring.
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All authors Kyle Verrier, Achille Nazaret, Joseph Futoma, Andrew C. Miller, Guillermo Sapiro
Computation and Language
In Machina N400: Pinpointing Where a Causal Language Model Detects Semantic Violations
Christos-Nikolaos Zacharopoulos and Revekka Kyriakoglou
How and where does a
transformer notice that a sentence has gone semantically off the rails? To explore this question, we evaluated the causal
language model (phi-2) using a carefully curated corpus, with sentences that concluded plausibly or implausibly. Our analysis focused on the hidden states sampled at each model layer. To investigate how violations are encoded, we utilized two complementary probes. First, we conducted a per-layer detection using a linear probe. Our findings revealed that a simple linear decoder struggled to distinguish between plausible and implausible endings in the lowest third of the model's layers. However, its accuracy sharply increased in the middle blocks, reaching a peak just before the top layers. Second, we examined the effective dimensionality of the encoded violation. Initially, the violation widens the representational subspace, followed by a collapse after a mid-stack bottleneck. This might indicate an exploratory phase that transitions into rapid consolidation. Taken together, these results contemplate the idea of
alignment with classical psycholinguistic findings in human reading, where semantic anomalies are detected only after syntactic resolution, occurring later in the online processing sequence.
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Computation and Language · Cross-listed from cs.LG
RAVEN++: Pinpointing Fine-Grained Violations in Advertisement Videos with Active Reinforcement Reasoning
Deyi Ji, Yuekui Yang, Liqun Liu et al. (+7 more)
Advertising (Ad) is a cornerstone of the digital economy, yet the moderation of
video advertisements remains a significant challenge due to their complexity and the need for precise violation localization. While recent advancements, such as the RAVEN model, have improved coarse-grained violation detection, critical gaps persist in fine-grained understanding, explainability, and generalization. To address these limitations, we propose RAVEN++, a novel framework that introduces three key innovations: 1) Active Reinforcement Learning (RL), which dynamically adapts training to samples of varying difficulty; 2) Fine-Grained Violation Understanding, achieved through hierarchical reward functions and
reasoning distillation; and 3) Progressive Multi-Stage Training, which systematically combines knowledge injection, curriculum-based passive RL, and active RL. Extensive experiments on both public and proprietary
datasets, on both offline scenarios and online deployed A/B Testing, demonstrate that RAVEN++ outperforms general-purpose LLMs and specialized models like RAVEN in terms of fine-grained violation understanding,
reasoning capabilities, and generalization ability.
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All authors Deyi Ji, Yuekui Yang, Liqun Liu, Peng Shu, Haiyang Wu, Shaogang Tang, Xudong Chen, Shaoping Ma, Tianrun Chen, Lanyun Zhu
Computation and Language
Epistemic Familiarity is Associated With Belief Stability in Large Language Models
Samantha Dies, Courtney Maynard, Germans Savcisens et al. (+1 more)
Large
language models (LLMs) are widely used as information sources, yet small changes in semantic assumptions can destabilize their beliefs. We introduce P-StaT (Perturbation Stability of Truth), a framework for evaluating belief stability under matched semantic perturbations in both representational and behavioral settings. Across 21 LLMs and three domains, we compare perturbations involving familiar Fictional statements against synthetically generated and unfamiliar Synthetic statements. Unfamiliar Synthetic perturbations generally induce greater epistemic instability than familiar Fictional perturbations, with behavioral belief retraction rates frequently exceeding 0.5 (50%). Finally, exploratory clustering analyses reveal recurring themes among retracted statements, including ambiguity, technical terminology, and obscure concepts. These results show that epistemic familiarity is systematically associated with stability under semantic reframing, suggesting that stability-based analyses can complement accuracy-based
benchmarks when evaluating LLM robustness and reliability. Code and data are available at https://github.com/samanthadies/P-StaT.
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All authors Samantha Dies, Courtney Maynard, Germans Savcisens, Tina Eliassi-Rad
Computation and Language · Cross-listed from cs.CV
From Pixels to Posts: Retrieval-Augmented Fashion Captioning and Hashtag Generation
Moazzam Umer Gondal, Hamad Ul Qudous, Daniya Siddiqui et al. (+1 more)
This paper introduces the
retrieval-augmented framework for automatic fashion caption and hashtag generation, combining multi-garment detection, attribute
reasoning, and Large
Language Model (LLM) prompting. The system aims to produce visually grounded, descriptive, and stylistically interesting text for fashion imagery, overcoming the limitations of end-to-end captioners that have problems with attribute fidelity and domain generalization. The pipeline combines a YOLO-based detector for multi-garment localization, k-means clustering for dominant color extraction, and a CLIP-FAISS
retrieval module for fabric and gender attribute inference based on a structured product index. These attributes, together with retrieved style examples, create a factual evidence pack that is used to guide an LLM to generate human-like captions and contextually rich hashtags. A fine-tuned BLIP model is used as a supervised baseline model for comparison. Experimental results show that the YOLO detector is able to obtain a mean Average Precision (mAP@0.5) of 0.71 for nine categories of garments. The RAG-LLM pipeline generates expressive attribute-aligned captions and achieves mean attribute coverage of 0.80 with full coverage at the 50% threshold in hashtag generation, whereas BLIP gives higher lexical overlap and lower generalization. The
retrieval-augmented approach exhibits better factual grounding, less
hallucination, and great potential for scalable deployment in various clothing domains. These results demonstrate the use of
retrieval-augmented generation as an effective and interpretable paradigm for automated and visually grounded fashion content generation.
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All authors Moazzam Umer Gondal, Hamad Ul Qudous, Daniya Siddiqui, Asma Ahmad Farhan
Computation and Language
Eliciting Chain-of-Thought in Base LLMs via Gradient-Based Representation Optimization
Zijian Wang, Yanxiang Ma and Chang Xu
Chain-of-Thought (CoT)
reasoning is a critical capability for large
language models (LLMs), enabling them to tackle com- plex multi-step tasks. While base LLMs, pre-trained on general text corpora, often struggle with
reasoning due to a lack of specialized training, recent studies reveal their latent reason- ing potential tied to hidden states. However, existing hidden state manipulation methods, such as linear activation steering, suffer from limitations due to their rigid and unconstrained nature, often leading to distribution shifts and degraded text quality. In this work, we propose a novel approach for elic- iting CoT
reasoning from base LLMs through hidden state manipulation grounded in probabilistic conditional generation. By reformulating the challenge as an optimization problem with a balanced likelihood and prior regularization framework, our method guides hidden states toward
reasoning-oriented trajectories while preserving linguistic coherence. Extensive evaluations across mathematical, commonsense, and logical
reasoning benchmarks demonstrate that our approach con- sistently outperforms existing steering methods, offering a theoretically principled and effective solution for enhancing
reasoning capabilities in base LLMs.
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Computation and Language
Emotion-Enhanced Multi-Task Learning with LLMs for Aspect Category Sentiment Analysis
Yaping Chai, Haoran Xie and Joe S. Qin
Aspect category sentiment analysis (ACSA) has achieved remarkable progress with large
language models (LLMs), yet existing approaches primarily emphasize sentiment polarity while overlooking the underlying emotional dimensions that shape sentiment expressions. This limitation hinders the model's ability to capture fine-grained affective signals toward specific aspect categories. To address this limitation, we introduce a novel
emotion-enhanced multi-task ACSA framework that jointly learns sentiment polarity and category-specific
emotions grounded in Ekman's six basic
emotions. Leveraging the generative capabilities of LLMs, our approach enables the model to produce emotional descriptions for each aspect category, thereby enriching sentiment representations with affective expressions. Furthermore, to ensure the accuracy and consistency of the generated
emotions, we introduce an
emotion refinement mechanism based on the Valence-Arousal-Dominance (VAD) dimensional framework. Specifically,
emotions predicted by the LLM are projected onto a VAD space, and those inconsistent with their corresponding VAD coordinates are re-annotated using a structured LLM-based refinement strategy. Experimental results demonstrate that our approach significantly outperforms strong baselines on all
benchmark datasets. This underlines the effectiveness of integrating affective dimensions into ACSA.
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Computation and Language
On the Optimality of Kinship Naming: an Information-theoretic Approach
Phong Le, Mees Lindeman and Raquel G. Alhama
The structure of naming systems in natural
languages hinges on a trade-off between high informativeness and low complexity. Focusing on the domain of kinship naming, we analyze such trade-off while addressing simplifying assumptions of prior work, namely: (i) universal communicative need across
languages, and (ii) optimal listeners. To that aim, we collect data from four different
languages, and analyze how different communicative needs and variations in the listener model influence the informativeness–complexity trade-off. Adopting a referential game setup from emergent communication, we further show that trade-off optimality is not only theoretically achievable but also emerges empirically in learned communication systems.
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Computation and Language
A symbolic Perl algorithm for the unification of Nahuatl word spellings
Juan-José Guzmán-Landa, Jesús Vázquez-Osorio, Juan-Manuel Torres-Moreno et al. (+6 more)
In this paper, we describe a symbolic model for the automatic orthographic unification of Nawatl text documents. Our model is based on
algorithms that we have previously used to analyze sentences in Nawatl, and on the corpus called $\pi$-yalli, consisting of texts in several Nawatl orthographies. Our automatic unification
algorithm implements linguistic rules in symbolic regular expressions. We also present a manual evaluation protocol that we have proposed and implemented to assess the quality of the unified sentences generated by our
algorithm, by testing in a sentence semantic task. We have obtained encouraging results from the evaluators for most of the desired features of our artificially unified sentences
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All authors Juan-José Guzmán-Landa, Jesús Vázquez-Osorio, Juan-Manuel Torres-Moreno, Ligia Quintana Torres, Miguel Figueroa-Saavedra, Martha-Lorena Avendaño-Garrido, Graham Ranger, Patricia Velázquez-Morales, Gerardo Eugenio Sierra Martínez
Computation and Language
A Multi-Agent LLM Framework for Multi-Domain Low-Resource In-Context NER via Knowledge Retrieval, Disambiguation and Reflective Analysis
Wenxuan Mu, Jinzhong Ning, Di Zhao et al. (+1 more)
In-context learning (ICL) with large
language models (LLMs) has emerged as a promising paradigm for named entity recognition (NER) in low-resource scenarios. However, existing ICL-based NER methods suffer from three key limitations: (1) reliance on dynamic
retrieval of annotated examples, which is problematic when annotated data is scarce; (2) limited generalization to unseen domains due to the LLM's insufficient internal domain knowledge; and (3) failure to incorporate external knowledge or resolve entity ambiguities. To address these challenges, we propose KDR-
Agent, a novel multi-
agent framework for multi-domain low-resource in-context NER that integrates Knowledge
retrieval, Disambiguation, and Reflective analysis. KDR-
Agent leverages natural-
language type definitions and a static set of entity-level contrastive demonstrations to reduce dependency on large annotated corpora. A central planner coordinates specialized
agents to (i) retrieve factual knowledge from Wikipedia for domain-specific mentions, (ii) resolve ambiguous entities via contextualized
reasoning, and (iii) reflect on and correct model predictions through structured self-assessment. Experiments across ten
datasets from five domains demonstrate that KDR-
Agent significantly outperforms existing zero-shot and few-shot ICL baselines across multiple LLM backbones. The code and data can be found at https://github.com/MWXGOD/KDR-
Agent.
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All authors Wenxuan Mu, Jinzhong Ning, Di Zhao, Yijia Zhang
Computation and Language
GraphMind: Theorem Selection and Conclusion Generation Framework with Dynamic GNN for LLM Reasoning
Yutong Li, Yitian Zhou, Xudong Wang et al. (+2 more)
Large
language models (LLMs) have demonstrated impressive capabilities in natural
language understanding and generation, including multi-step
reasoning such as mathematical proving. However, existing approaches often lack an explicit and dynamic mechanism to structurally represent and evolve intermediate
reasoning states, which limits their ability to perform context-aware
theorem selection and iterative conclusion generation. To address these challenges, we propose GraphMind, a novel dynamic graph-based framework that integrates the graph neural network (GNN) with LLMs to iteratively select
theorems and generate intermediate conclusions for multi-step
reasoning. Our method models the
reasoning process as a heterogeneous evolving graph, where nodes represent conditions,
theorems, and conclusions, while edges capture logical dependencies between nodes. By encoding the current
reasoning state with GNN and leveraging semantic matching for
theorem selection, our framework enables context-aware, interpretable, and structured
reasoning in a closed-loop manner. Experiments on various question-answering (QA)
datasets demonstrate that our proposed GraphMind method achieves consistent performance improvements and significantly outperforms existing baselines in multi-step
reasoning, validating the effectiveness and generalizability of our approach.
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All authors Yutong Li, Yitian Zhou, Xudong Wang, GuoChen, Caiyan Qin
Computation and Language
Logic of Montage
Hayami Takahashi and Kensuke Takahashi
In expressing
emotions, as an expression form separate from natural
language, we propose an alternative form that complements natural
language, acting as a proxy or window for emotional states. First, we set up an expression form "Effect of Contradictory Structure." "Effect of Contradictory Structure" is not static but dynamic. Effect in "Effect of Contradictory Structure" is unpleasant or pleasant, and the orientation to avoid that unpleasantness is considered pseudo-expression of will. Second, "Effect of Contradictory Structure" can be overlapped with each other. This overlapping operation is called "montage." A broader "Structure" that includes related "Effect of Contradictory Structure" and "Effect of Structure" are set up. Montage produces "Effect of Structure". In montage, it is necessary to set something like "strength," so we adopted Deleuze and Deleuze/Guattari's word "intensity" and set it as an element of our model. We set up a general theoretical framework - Word Import Between Systems (Models) and justified the import of "intensity" through Austin's use of the word "force." "Effect of Structure" process is demonstrated using the example of proceeding to the next level of education.
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Computation and Language · Cross-listed from cs.CR
Understanding and Mitigating Over-refusal for Large Language Models via Representation Intervention
Junbo Zhang, Ran Chen, Qianli Zhou et al. (+2 more)
Large
language models (LLMs) demonstrate powerful capabilities across various natural
language processing tasks,yet their inherent safety vulnerabilities undermine the reliable application of LLMs in real-world scenarios. To enhance LLM safety, various jailbreak defense methods have been proposed to guard against harmful outputs. However, improvements in model safety often come at the cost of severe over-refusal, failing to strike a good balance between safety and usability. This phenomenon is a critical reliability degradation issue in LLM intelligent systems, failing to strike a good balance between safety defense effectiveness and system usability reliability. In this paper, we first analyze the causes of over-refusal from a representation perspective, revealing that LLMs are unable to effectively distinguish between over-refusal samples and malicious samples. Based on this, we propose to mitigate overrefusal by intervening in the safety representation space of LLMs. Our method incorporates two core strategies: (1) OverlapAware Loss Weighting, which determines the erasure weight for malicious samples by quantifying their similarity to overrefusal samples in the representation space, and (2) ContextAware Augmentation, which supplements the necessary context for rejection decisions by adding harmful prefixes before rejection responses. Experiments demonstrate that our method achieves a better trade-off between mitigating over-refusal and maintaining safety, compared with existing approaches. This paper also aims to encourage researchers to consider the reliability of defending methods against jailbreak attacks from both the perspectives of safety and over-refusal.
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All authors Junbo Zhang, Ran Chen, Qianli Zhou, Xinyang Deng, Wen Jiang
Computation and Language · Cross-listed from stat.ML
Classification EM-PCA for clustering and embedding
Zineddine Tighidet, Lazhar Labiod and Mohamed Nadif
The mixture model is undoubtedly one of the greatest contributions to clustering. For continuous data, Gaussian models are often used and the Expectation-Maximization (EM)
algorithm is particularly suitable for estimating parameters from which clustering is inferred. If these models are particularly popular in various domains including image clustering, they however suffer from the dimensionality and also from the slowness of convergence of the EM
algorithm. However, the Classification EM (CEM)
algorithm, a classifying version, offers a fast convergence solution while dimensionality reduction still remains a challenge. Thus we propose in this paper an
algorithm combining simultaneously and non-sequentially the two tasks –Data
embedding and Clustering– relying on Principal Component Analysis (PCA) and CEM. We demonstrate the interest of such approach in terms of clustering and data
embedding. We also establish different connections with other clustering approaches.
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Computation and Language
Knowledge-based Graphical Method for Safety Signal Detection in Clinical Trials
Francois Vandenhende, Anna Georgiou, Michalis Georgiou et al. (+3 more)
We present a graphical, knowledge-based method for reviewing treatment-emergent adverse events (AEs) in clinical trials. The approach enhances MedDRA by adding a hidden medical knowledge layer (Safeterm) that captures semantic relationships between terms in a 2-D map. Using this layer, AE Preferred Terms can be regrouped automatically into similarity clusters, and their association to the trial disease may be quantified. The Safeterm map is available online and connected to aggregated AE incidence tables from ClinicalTrials.gov. For signal detection, we compute treatment-specific disproportionality metrics using shrinkage incidence ratios. Cluster-level EBGM values are then derived through precision-weighted aggregation. Two visual outputs support interpretation: a semantic map showing AE incidence and an expectedness-versus-disproportionality plot for rapid signal detection. Applied to three legacy trials, the automated method clearly recovers all expected safety signals. Overall, augmenting MedDRA with a medical knowledge layer improves clarity, efficiency, and accuracy in AE interpretation for clinical trials.
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All authors Francois Vandenhende, Anna Georgiou, Michalis Georgiou, Theodoros Psaras, Ellie Karekla, Elena Hadjicosta
Computation and Language · Cross-listed from cs.LG
SWAN: Sparse Winnowed Attention for Reduced Inference Memory via Decompression-Free KV-Cache Compression
Santhosh G S, Saurav Prakash and Balaraman Ravindran
Large
Language Models (LLMs) face a significant bottleneck during autoregressive inference due to the massive
memory footprint of the Key-Value (KV) cache. Existing compression techniques like
token eviction, quantization, or other low-rank methods often risk information loss, have fixed limits, or introduce significant computational overhead from explicit decompression steps. In this work, we introduce SWAN, a novel, fine-tuning-free framework that eliminates this overhead. Our method uses an offline orthogonal
matrix to rotate and prune the KV-cache, which is then used directly in the
attention computation without any reconstruction. Our extensive experiments demonstrate that SWAN, augmented with a small dense buffer, offers a robust trade-off, maintaining performance close to the uncompressed baseline even at aggressive 50-60%
memory savings per-
token on KV-cache. A key advantage is its runtime-tunable compression level, allowing operators to dynamically adjust the
memory footprint, a flexibility absent in methods requiring fixed offline configurations. This combination of a decompression-free design, high performance under compression, and adaptability makes SWAN a practical and efficient solution for serving LLMs with long contexts.
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Computation and Language
Skeletons Matter: Dynamic Data Augmentation for Text-to-Query
Yuchen Ji, Bo Xu, Jie Shi et al. (+5 more)
The task of translating natural
language questions into query
languages has long been a central focus in semantic parsing. Recent advancements in Large
Language Models (LLMs) have significantly accelerated progress in this field. However, existing studies typically focus on a single query
language, resulting in methods with limited generalizability across different
languages. In this paper, we formally define the Text-to-Query task paradigm, unifying semantic parsing tasks across various query
languages. We identify query skeletons as a shared optimization target of Text-to-Query tasks, and propose a general dynamic data augmentation framework that explicitly diagnoses model-specific weaknesses in handling these skeletons to synthesize targeted training data. Experiments on four Text-to-Query
benchmarks demonstrate that our method achieves state-of-the-art performance using only a small amount of synthesized data, highlighting the efficiency and generality of our approach and laying a solid foundation for unified research on Text-to-Query tasks. We release our code at https://github.com/jjjycaptain/Skeletron.
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All authors Yuchen Ji, Bo Xu, Jie Shi, Jiaqing Liang, Deqing Yang, Yu Mao, Hai Chen, Yanghua Xiao
Computation and Language
Look It Up: Analysing Internal Web Search Capabilities of Modern LLMs
Sahil Kale
Modern large
language models increasingly integrate internal web-based
retrieval to provide real-time answers, yet it remains unclear how effectively these systems identify information need, trigger
retrieval, and use retrieved evidence. To understand these parameters better, we evaluate the necessity and effectiveness of internal web search through an external lens in closed-source LLMs, without access to model parameters or internal configuration. Our evaluation method comprises a static split of 783 temporally anchored factual queries answerable from pre-cutoff knowledge, designed to test whether
retrieval is invoked based on factual uncertainty, and a dynamic split of 288 post-cutoff queries that require up-to-date information, designed to evaluate
retrieval effectiveness under unavoidable information need. We experiment across four models across two model families and scales. Across models, enabling
retrieval yields substantial accuracy gains on the static split, but systematically degrades confidence calibration. On the dynamic split, models frequently invoke
retrieval yet remain below 70 percent accuracy, with failures dominated by query formulation and source selection errors rather than integration of retrieved content. While
retrieval is inexpensive to invoke and can be selectively beneficial, repeated
retrieval attempts rarely recover from early failures, and confidence becomes inflated once
retrieval is available. Overall, internal web-based
retrieval functions effectively as a low-latency verification mechanism, but falls short as a reliable IR pipeline, highlighting the need for improved
retrieval triggering, query formulation, and evidence-aware confidence calibration in web-enabled LLMs.
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Computation and Language · Cross-listed from cs.LG
How Learning Rate Decay Wastes Your Best Data in Curriculum-Based LLM Pretraining
Kairong Luo, Zhenbo Sun, Haodong Wen et al. (+5 more)
Due to the scarcity of high-quality data, large
language models (LLMs) are often trained on mixtures of data with varying quality levels, even after sophisticated data curation. A natural approach to better leverage high-quality data is curriculum-based pretraining, where the model is trained on data sorted in ascending order of quality as determined by a quality metric. However, prior studies have reported limited improvements from such curriculum-based pretraining strategies. This work identifies a critical factor constraining these methods: the incompatibility between the ascending data quality order and the decaying learning rate (LR) schedule. We find that while curriculum-based training substantially outperforms random shuffling when using a constant LR, its advantage diminishes under standard LR decay schedules. Our experiments show this incompatibility can be mitigated by two simple strategies: (1) employing a more moderate LR decay schedule, where the final LR is only moderately smaller than the peak LR, and (2) replacing LR decay with model averaging, i.e., computing a weighted average of the final few checkpoints. By combining these strategies, we improve the average score on a suite of standard
benchmarks by 1.64% over random shuffling, without additional data refinement. Validated on 1.5B-parameter models trained over 30B
tokens with various data-quality metrics, our findings call for a re-evaluation of curriculum-based LLM pretraining and underscore the potential of co-designing data curricula with optimization methods.
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All authors Kairong Luo, Zhenbo Sun, Haodong Wen, Xinyu Shi, Jiarui Cui, Chenyi Dang, Kaifeng Lyu, Wenguang Chen
Computation and Language
Reproducibility Study of Large Language Model Bayesian Optimization
Adam Rychert, Gasper Spagnolo and Evgenii Posashkov
In this reproducibility study, we revisit the LLAMBO framework of Daxberger et al. (2024), a prompting-based
Bayesian optimization (BO) method that uses large
language models as discriminative surrogates and acquisition optimizers via text-only interactions. We replicate the core Bayesmark and HPOBench experiments under the original evaluation protocol, but replace GPT-3.5 with the open-weight Llama 3.1 70B model used for all text encoding components. Our results broadly confirm the main claims of LLAMBO. Contextual warm starting via textual problem and hyperparameter descriptions substantially improves early regret behaviour and reduces variance across runs. LLAMBO's discriminative surrogate is weaker than GP or SMAC as a pure single task regressor, yet benefits from cross task semantic priors induced by the
language model. Ablations that remove textual context markedly degrade predictive accuracy and calibration, while the LLAMBO candidate sampler consistently generates higher quality and more diverse proposals than TPE or random sampling. Experiments with smaller backbones (Gemma 27B, Llama 3.1 8B) yield unstable or invalid predictions, suggesting insufficient capacity for reliable surrogate behaviour. Overall, our study shows that the LLAMBO architecture is robust to changing the
language model backbone and remains effective when instantiated with Llama 3.1 70B.
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Computation and Language
CoreEval: Automatically Building Contamination-Resilient Datasets with Real-World Knowledge toward Reliable LLM Evaluation
Jingqian Zhao, Bingbing Wang, Geng Tu et al. (+5 more)
Data contamination poses a significant challenge to the
fairness of LLM evaluations in natural
language processing tasks by inadvertently exposing models to test data during training. Current studies attempt to mitigate this issue by modifying existing
datasets or generating new ones from freshly collected information. However, these methods fall short of ensuring contamination-resilient evaluation, as they fail to fully eliminate pre-existing knowledge from models or preserve the semantic complexity of the original
datasets. To address these limitations, we propose CoreEval, a Contamination-resilient Evaluation strategy for automatically updating data with real-world knowledge. This approach begins by extracting entity relationships from the original data and leveraging the GDELT database to retrieve relevant, up-to-date knowledge. The retrieved knowledge is then recontextualized and integrated with the original data, which is refined and restructured to ensure semantic coherence and enhanced task relevance. Ultimately, a robust data reflection mechanism is employed to iteratively verify and refine labels, ensuring consistency between the updated and original
datasets. Extensive experiments on updated
datasets validate the robustness of CoreEval, demonstrating its effectiveness in mitigating performance overestimation caused by data contamination.
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All authors Jingqian Zhao, Bingbing Wang, Geng Tu, Yice Zhang, Qianlong Wang, Bin Liang, Jing Li, Ruifeng Xu
Computation and Language
Think Before You Prune: Selective Self-Generated Calibration for Pruning Large Reasoning Models
Yang Xiang, Yixin Ji, Juntao Li et al. (+1 more)
Large
Reasoning Models (LRMs) have demonstrated remarkable performance on complex
reasoning benchmarks. However, their long chain-of-thought
reasoning processes incur significant inference overhead.
Pruning has emerged as a promising approach to reducing computational costs. However, existing efforts have primarily focused on large
language models (LLMs), while
pruning LRMs remains unexplored. In this work, we conduct the first empirical study on
pruning LRMs and show that directly applying existing
pruning techniques fails to yield satisfactory results. Our findings indicate that using self-generated
reasoning data for calibration can substantially improve
pruning performance. We further investigate how the difficulty and length of
reasoning data affect
pruning outcomes. Our analysis reveals that challenging and moderately long self-generated
reasoning data serve as ideal calibration data. Based on these insights, we propose a Selective Self-Generated
Reasoning (SSGR) data construction strategy to provide effective calibration data for
pruning LRMs. Experimental results on the DeepSeek-R1-Distill model series validate that our strategy improves the
reasoning ability of pruned LRMs by 10%-13% compared to general
pruning methods.
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All authors Yang Xiang, Yixin Ji, Juntao Li, Min Zhang
Computation and Language
Generating Reading Comprehension Exercises with Large Language Models for Educational Applications
Xingyu Huang, Fei Jiang and Jianli Xiao
With the rapid development of large
language models (LLMs), the applications of LLMs have grown substantially. In the education domain, LLMs demonstrate significant potential, particularly in automatic text generation, which enables the creation of intelligent and adaptive learning content. This paper proposes a new LLMs framework, which is named as Reading Comprehension Exercise Generation (RCEG). It can generate high-quality and personalized English reading comprehension exercises automatically. Firstly, RCEG uses fine-tuned LLMs to generate content candidates. Then, it uses a discriminator to select the best candidate. Finally, the quality of the generated content has been improved greatly. To evaluate the performance of RCEG, a dedicated
dataset for English reading comprehension is constructed to perform the experiments, and comprehensive evaluation metrics are used to analyze the experimental results. These metrics include content diversity, factual accuracy, linguistic toxicity, and pedagogical
alignment. Experimental results show that RCEG significantly improves the relevance and cognitive appropriateness of the generated exercises.
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Computation and Language
FanarGuard: A Culturally-Aware Moderation Filter for Arabic Language Models
Masoomali Fatehkia, Enes Altinisik and Husrev Taha Sencar
Content moderation filters are a critical safeguard against
alignment failures in
language models. Yet most existing filters focus narrowly on general safety and overlook cultural context. In this work, we introduce FanarGuard, a bilingual moderation filter that evaluates both safety and cultural
alignment in Arabic and English. We construct a
dataset of over 468K
prompt and response pairs, drawn from synthetic and public
datasets, scored by a panel of LLM judges on harmlessness and cultural awareness, and use it to train two filter variants. To rigorously evaluate cultural
alignment, we further develop the first
benchmark targeting Arabic cultural contexts, comprising over 1k norm-sensitive
prompts with LLM-generated responses annotated by human raters. Results show that FanarGuard achieves stronger agreement with human annotations than inter-annotator reliability, while matching the performance of state-of-the-art filters on safety
benchmarks. These findings highlight the importance of integrating cultural awareness into moderation and establish FanarGuard as a practical step toward more context-sensitive safeguards.
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