GenAI4ELab/papercli-papers huggingface dataset:
Demystify Verbosity Compensation Behavior of Large Language Models
Authors: Yusen Zhang; Sarkar Snigdha Sarathi Das; Rui Zhang
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Recent work has revealed Large Language Models (LLMs) often exhibit undesirable behaviors, such as hallucination and toxicity, limiting their reliability and broader adoption. In this paper, we discover an understudied type of undesirable behavior of LLMs, which we term Verbosity Compensation (VC). VC is similar to the hesitation behavior of humans under uncertainty, compensating with excessive words such as repeating questions, introducing ambiguity, or providing excessive enumeration. We present the first work that analyzes Verbosity Compensation, explores its causes, and proposes a simple mitigating approach. Our experiments on five datasets of knowledge and reasoning-based QA tasks with 14 LLMs, reveal three conclusions. 1) A pervasive presence of VC across all models and all datasets. 2) The large performance gap between verbose and concise responses. We also demonstrate that this difference does not naturally diminish as LLM capability increases. 3) Higher uncertainty exhibited by VC responses across all five datasets, suggesting a strong connection between verbosity and model uncertainty. We propose a simple yet effective cascade algorithm that replaces the verbose responses with the other model-generated responses, alleviating the VC of the Mistral model from 63.81% to 16.16% on the Qasper dataset.
On the Role of Unobserved Sequences on Sample-based Uncertainty Quantification for LLMs
Authors: Lucie Kunitomo-Jacquin; Edison Marrese-Taylor; Ken Fukuda
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Quantifying uncertainty in large language models (LLMs) is important for safety-critical applications because it helps spot incorrect answers, known as hallucinations. One major trend of uncertainty quantification methods is based on estimating the entropy of the distribution of the LLM’s potential output sequences. This estimation is based on a set of output sequences and associated probabilities obtained by querying the LLM several times. In this paper, we advocate and experimentally and show that the probability of unobserved sequences plays a crucial role, and we recommend future research to integrate it to enhance such LLM uncertainty quantification methods.
Confidence-Based Response Abstinence: Improving LLM Trustworthiness via Activation-Based Uncertainty Estimation
Authors: Zhiqi Huang; Vivek Datla; Chenyang Zhu; Alfy Samuel; Daben Liu; Anoop Kumar; Ritesh Soni
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: We propose a method for confidence estimation in retrieval-augmented generation (RAG) systems that aligns closely with the correctness of large language model (LLM) outputs. Confidence estimation is especially critical in high-stakes domains such as finance and healthcare, where the cost of an incorrect answer outweighs that of not answering the question. Our approach extends prior uncertainty quantification methods by leveraging raw feed-forward network (FFN) activations as auto-regressive signals, avoiding the information loss inherent in token logits and probabilities after projection and softmax normalization. We model confidence prediction as a sequence classification task, and regularize training with a Huber loss term to improve robustness against noisy supervision. Applied in a real-world financial industry customer-support setting with complex knowledge bases, our method outperforms strong baselines and maintains high accuracy under strict latency constraints. Experiments on Llama 3.1 8B model show that using activations from only the 16th layer preserves accuracy while reducing response latency. Our results demonstrate that activation-based confidence modeling offers a scalable, architecture-aware path toward trustworthy RAG deployment.
Amortized Bayesian Meta-Learning for Low-Rank Adaptation of Large Language Models
Authors: Liyi Zhang; Jake C. Snell; Thomas L. Griffiths
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Fine-tuning large language models (LLMs) with low-rank adaptaion (LoRA) is a cost-effective way to incorporate information from a specific dataset. However, it is often unclear how well the fine-tuned LLM will generalize, i.e., how well it will perform on unseen datasets. Methods have been proposed to improve generalization by optimizing with in-context prompts, or by using meta-learning to fine-tune LLMs. However, these methods are expensive in memory and computation, requiring either long-context prompts or saving copies of parameters and using second-order gradient updates. To address these challenges, we propose Amortized Bayesian Meta-Learning for LoRA (ABMLL). This method builds on amortized Bayesian meta-learning for smaller models, adapting this approach to LLMs while maintaining its computational efficiency. We reframe task-specific and global parameters in the context of LoRA and use a set of new hyperparameters to balance reconstruction accuracy and the fidelity of task-specific parameters to the global ones. ABMLL provides effective generalization and scales to large models such as Llama3-8B. Furthermore, as a result of using a Bayesian framework, ABMLL provides improved uncertainty quantification. We test ABMLL on Unified-QA and Crossfit datasets and find that it outperforms existing methods on these benchmarks in terms of both accuracy and expected calibration error.
Towards Trustworthy Summarization of Cardiovascular Articles: A Factuality-and-Uncertainty-Aware Biomedical LLM Approach
Authors: Eleni Partalidou; Tatiana Passali; Chrysoula Zerva; Grigorios Tsoumakas; Sophia Ananiadou
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: While large, biomedical documents with complex terminology are in need of being understood more easily and efficiently, summarizing this kind of content can be problematic, as Large Language Models (LLMs) aren’t always trustworthy. Considering the importance of comprehending Cardiovascular Diseases, we study in depth the ability of different state-of-the-art biomedical LLMs to generate factual and certain summaries in this topic, and examine which generation choices can influence their trustworthiness. To that end, besides using factuality metrics, we employ techniques for token-level uncertainty estimation, an area that has received little attention from the scientific community. Our results reveal dissimilarities between LLMs and generation methods, and highlight connections between factuality and uncertainty metrics, thereby laying the groundwork for further investigation in the area.
Causal Understanding by LLMs: The Role of Uncertainty
Authors: Oscar William Lithgow-Serrano; Vani Kanjirangat; Alessandro Antonucci
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Recent papers show LLMs achieve near-random accuracy in causal relation classification, raising questions about whether such failures arise from limited pretraining exposure or deeper representational gaps. We investigate this under uncertainty-based evaluation, testing whether pretraining exposure to causal examples improves causal understanding using >18K PubMed sentences—half from The Pile corpus, half post-2024—across seven models (Pythia-1.4B/7B/12B, GPT-J-6B, Dolly-7B/12B, Qwen-7B). We analyze model behavior through: (i) causal classification, where the model identifies causal relationships in text, and (ii) verbatim memorization probing, where we assess whether the model prefers previously seen causal statements over their paraphrases. Models perform four-way classification (direct/conditional/correlational/no-relationship) and select between originals and their generated paraphrases. Results show almost identical accuracy on seen/unseen sentences (p>0.05), no memorization bias (24.8% original selection), output distribution over the possible options almost flat — with entropic values near the maximum (1.35/1.39), confirming random guessing. Instruction-tuned models show severe miscalibration (Qwen: >95% confidence, 32.8% accuracy, ECE=0.49). Conditional relations induce highest entropy (+11% vs direct). These findings suggest that failures in causal understanding arise from the lack of structured causal representation, rather than insufficient exposure to causal examples during pretraining.
It Depends: Resolving Referential Ambiguity in Minimal Contexts with Commonsense Knowledge
Authors: Lukas Ellinger; Georg Groh
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Ambiguous words or underspecified references require interlocutors to resolve them, often by relying on shared context and commonsense knowledge. Therefore, we systematically investigate whether Large Language Models (LLMs) can leverage commonsense to resolve referential ambiguity in multi-turn conversations and analyze their behavior when ambiguity persists. Further, we study how requests for simplified language affect this capacity. Using a novel multilingual evaluation dataset, we test DeepSeek v3, GPT-4o, Qwen3-32B, GPT-4o-mini, and Llama-3.1-8B via LLM-as-Judge and human annotations. Our findings indicate that current LLMs struggle to resolve ambiguity effectively: they tend to commit to a single interpretation or cover all possible references, rather than hedging or seeking clarification. This limitation becomes more pronounced under simplification prompts, which drastically reduce the use of commonsense reasoning and diverse response strategies. Fine-tuning Llama-3.1-8B with Direct Preference Optimization substantially improves ambiguity resolution across all request types. These results underscore the need for advanced fine-tuning to improve LLMs’ handling of ambiguity and to ensure robust performance across diverse communication styles.
Read Your Own Mind: Reasoning Helps Surface Self-Confidence Signals in LLMs
Authors: Jakub Podolak; Rajeev Verma
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: We study the source of uncertainty in DeepSeek R1-32B by analyzing its self-reported verbal confidence on question answering (QA) tasks. In the default answer-then-confidence setting, the model is regularly over-confident, whereas semantic entropy - obtained by sampling many responses - remains reliable. We hypothesize that this is because of semantic entropy’s larger test-time compute, which lets us explore the model’s predictive distribution. We show that granting DeepSeek the budget to explore its distribution by forcing a long chain-of-thought before the final answer greatly improves its verbal score effectiveness, even on simple fact-retrieval questions that normally require no reasoning. Our analysis concludes that reliable uncertainty estimation requires explicit exploration of the generative space, and self-reported confidence is trustworthy only after such exploration.
Calibrating Language Models for Neural Ranking under Noisy Supervision with Relaxed Labels
Authors: Arnab Sharma; Daniel Vollmers; Axel-Cyrille Ngonga Ngomo
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: In recent years, we have seen an increased usage of neural ranking models in the information retrieval domain. Although language model-based rankers have shown significant progress in performing ranking tasks, little to no work has addressed the issue of fine-tuning them in the presence of label noise in the training data. In a general learning setting, training models in the presence of noisy labeled data is studied extensively. To this end, confidence calibration approaches have shown significant promise; however, their usage in training neural ranking models is relatively less studied. In this work, we address this gap by adapting and analyzing regularization-based calibration approaches to reduce the effect of label noise in ranking tasks. Specifically, we study label relaxation in neural ranking models. We demonstrate the effectiveness of this approach by performing extensive evaluations comparing the label relaxation approach to standard loss functions. Additionally, we analyze the calibration error associated with the loss functions.After evaluating on five different noise levels, two different ranking models, and four diverse ranking datasets, the results suggest that label relaxation can improve the performance of the ranking models under noisy labels. Furthermore, we find that label relaxation reduces calibration error, although it suggests a better metric to be used for neural ranking models.
ERGO: Entropy-guided Resetting for Generation Optimization in Multi-turn Language Models
Authors: Haziq Mohammad Khalid; Athikash Jeyaganthan; Timothy Do; Yicheng Fu; Vasu Sharma; Sean O’Brien; Kevin Zhu
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Large Language Models (LLMs) suffer significant performance degradation in multi-turn conversations when information is presented incrementally. Given that multi-turn conversations characterize everyday interactions with LLMs, this degradation poses a severe challenge to real world usability. We hypothesize that abrupt increases in model uncertainty signal misalignment in multi-turn LLM interactions, and we exploit this insight to dynamically realign conversational context. We introduce ERGO (Entropy-guided Resetting for Generation Optimization), which continuously quantifies internal uncertainty via Shannon entropy over next token distributions and triggers adaptive prompt consolidation when a sharp spike in entropy is detected. By treating uncertainty as a first class signal rather than a nuisance to eliminate, ERGO embraces variability in language and modeling, representing and responding to uncertainty. In multi-turn tasks with incrementally revealed instructions, ERGO yields a 56.6% average performance gain over standard baselines, increases aptitude (peak performance capability) by 24.7%, and decreases unreliability (variability in performance) by 35.3%, demonstrating that uncertainty aware interventions can improve both accuracy and reliability in conversational AI.
Towards Open-Ended Discovery for Low-Resource NLP
Authors: Bonaventure F. P. Dossou; Henri Aïdasso
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Natural Language Processing (NLP) for low-resource languages remains fundamentally constrained by the lack of textual corpora, standardized orthographies, and scalable annotation pipelines. While recent advances in large language models have improved cross-lingual transfer, they remain inaccessible to underrepresented communities due to their reliance on massive, pre-collected data and centralized infrastructure. In this position paper, we argue for a paradigm shift toward open-ended, interactive language discovery, where AI systems learn new languages dynamically through dialogue rather than static datasets. We contend that the future of language technology, particularly for low-resource and under-documented languages, must move beyond static data collection pipelines toward interactive, uncertainty-driven discovery, where learning emerges dynamically from human-machine collaboration instead of being limited to pre-existing datasets. We propose a framework grounded in joint human-machine uncertainty, combining epistemic uncertainty from the model with hesitation cues and confidence signals from human speakers to guide interaction, query selection, and memory retention. This paper is a call to action: we advocate a rethinking of how AI engages with human knowledge in under-documented languages, moving from extractive data collection toward participatory, co-adaptive learning processes that respect and empower communities while discovering and preserving the world's linguistic diversity. This vision aligns with principles of human-centered AI, emphasizing interactive, cooperative model building between AI systems and speakers.
Can Vision-Language Models Infer Speaker’s Ignorance? The Role of Visual and Linguistic Cues
Authors: Ye-eun Cho; Yunho Maeng
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: This study investigates whether vision-language models (VLMs) can perform pragmatic inference, focusing on ignorance implicatures, utterances that imply the speaker’s lack of precise knowledge. To test this, we systematically manipulated contextual cues: the visually depicted situation (visual cue) and QUD-based linguistic prompts (linguistic cue). When only visual cues were provided, three state-of-the-art VLMs (GPT-4o, Gemini 1.5 Pro, and Claude 3.5 sonnet) produced interpretations largely based on the lexical meaning of the modified numerals. When linguistic cues were added to enhance contextual informativeness, Claude exhibited more human-like inference by integrating both types of contextual cues. In contrast, GPT and Gemini favored precise, literal interpretations. Although the influence of contextual cues increased, they treated each contextual cue independently and aligned them with semantic features rather than engaging in context-driven reasoning. These findings suggest that although the models differ in how they handle contextual cues, Claude’s ability to combine multiple cues may signal emerging pragmatic competence in multimodal models.
DeLTa: A Decoding Strategy based on Logit Trajectory Prediction Improves Factuality and Reasoning Ability
Authors: Yunzhen He; Yusuke Takase; Yoichi Ishibashi; Hidetoshi Shimodaira
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Large Language Models (LLMs) are increasingly being used in real-world applications. However, concerns about the reliability of the content they generate persist, as it frequently deviates from factual correctness or exhibits deficiencies in logical reasoning. This paper proposes a novel decoding strategy aimed at enhancing both factual accuracy and inferential reasoning without requiring any modifications to the architecture or pre-trained parameters of LLMs. Our approach adjusts next-token probabilities by analyzing the trajectory of logits from lower to higher layers in Transformers and applying linear regression. We find that this Decoding by Logit Trajectory-based approach (DeLTa) effectively reinforces factuality and reasoning while mitigating incorrect generation. Experiments on TruthfulQA demonstrate that DeLTa attains up to a 4.9% improvement over the baseline. Furthermore, it enhances performance by up to 8.1% on StrategyQA and 7.3% on GSM8K, both of which demand strong reasoning capabilities.
Investigating Factuality in Long-Form Text Generation: The Roles of Self-Known and Self-Unknownan
Authors: Lifu Tu; Rui Meng; Shafiq Joty; Yingbo Zhou; Semih Yavuz
Venue: EMNLP 2025 (Proceedings of the 2nd Workshop on Uncertainty-Aware NLP (UncertaiNLP 2025))

Abstract: Large language models (LLMs) have demonstrated strong capabilities in text understanding and generation. However, they often lack factuality, producing a mixture of true and false in- formation, especially in long-form generation. In this work, we investigates the factuality of long-form text generation across various large language models (LLMs), including GPT-4, Gemini-1.5-Pro, Claude-3-Opus, Llama-3-70B, and Mistral. Our analysis reveals that factuality tend to decline in later sentences of the generated text, accompanied by a rise in the number of unsupported claims. Furthermore, we explore the effectiveness of different evaluation settings to assess whether LLMs can accurately judge the correctness of their own outputs: Self- Known (the percentage of supported atomic claims, decomposed from LLM outputs, that the corresponding LLMs judge as correct) and Self-Unknown (the percentage of unsupported atomic claims that the corresponding LLMs judge as incorrect). The results indicate that even advanced models fail to achieve perfect Self-Known scores, while their Self-Unknown scores remain notably above zero, reflecting ongoing uncertainty in their self-assessments. Moreover, we find a correlation between higher Self-Known scores and improved factuality, while higher Self-Unknown scores are associated with lower factuality. Even without sig nificant changes in the models’ self-judgment (Self-Known and Self-Unknown), the number of unsupported claims can increases, likely as an artifact of long-form generation. Additional Retrieval-Augmented Generation (RAG) experiments also show the limitations of current LLMs in long-form generation, and provide the more research is needed to improve factuality in long-form text generation.
Seeing Symbols, Missing Cultures: Probing Vision-Language Models’ Reasoning on Fire Imagery and Cultural Meaning
Authors: Haorui Yu; Yang Zhao; Yijia Chu; Qiufeng Yi
Venue: EMNLP 2025 (Proceedings of the 9th Widening NLP Workshop)

Abstract: Vision-Language Models (VLMs) often appearculturally competent but rely on superficial pat.tern matching rather than genuine cultural understanding. We introduce a diagnostic framework to probe VLM reasoning on fire-themedcultural imagery through both classification andexplanation analysis. Testing multiple modelson Western festivals, non-Western traditions.and emergency scenes reveals systematic biases: models correctly identify prominent Western festivals but struggle with underrepresentedcultural events, frequently offering vague labelsor dangerously misclassifying emergencies ascelebrations. These failures expose the risksof symbolic shortcuts and highlight the needfor cultural evaluation beyond accuracy metrics to ensure interpretable and fair multimodalsystems.
GPT4AMR: Does LLM-based Paraphrasing Improve AMR-to-text Generation Fluency?
Authors: Jiyuan Ji; Shira Wein
Venue: EMNLP 2025 (Proceedings of the 9th Widening NLP Workshop)

Abstract: Abstract Meaning Representation (AMR) is a graph-based semantic representation that has been incorporated into numerous downstream tasks, in particular due to substantial efforts developing text-to-AMR parsing and AMR-to-text generation models. However, there still exists a large gap between fluent, natural sentences and texts generated from AMR-to-text generation models. Prompt-based Large Language Models (LLMs), on the other hand, have demonstrated an outstanding ability to produce fluent text in a variety of languages and domains. In this paper, we investigate the extent to which LLMs can improve the AMR-to-text generated output fluency post-hoc via prompt engineering. We conduct automatic and human evaluations of the results, and ultimately have mixed findings: LLM-generated paraphrases generally do not exhibit improvement in automatic evaluation, but outperform baseline texts according to our human evaluation. Thus, we provide a detailed error analysis of our results to investigate the complex nature of generating highly fluent text from semantic representations.