Computation and Language
Subtitle-Aligned Fine-Tuning of Whisper for Swiss German ASR: Benchmark Contamination, Convention Mismatch, and an Honest Baseline at 25.6% WER (13.8% cWER)
Felix Akeret
We present a systematic study of fine-tuning OpenAI's Whisper large-v3 for Swiss German ASR, using 1,367 hours of broadcast
speech paired with Standard German subtitles as weak supervision. Through 16 iterative training runs on an NVIDIA DGX Spark (Grace Blackwell, 128 GB unified
memory, up to 1 PFLOP FP4), we compare LoRA and full fine-tuning of the 1.55B-parameter model, investigate
hallucination root causes, and quantify the effect of data quality, subtitle
alignment, and training strategy. Our best model achieves 25.6% measured WER on the All Swiss German Dialects Test Set (ASGDTS) in an honest evaluation on strictly disjoint data. A harmonized error analysis separating genuine errors from valid stylistic variation (tense, word order, Swiss orthography) yields a content WER (cWER) of 13.8%, counting only actual recognition failures. Bias-corrected estimation reduces this to 8.5%, suggesting the true error rate is roughly one third of measured WER. We demonstrate that published state-of-the-art Swiss German ASR results (17.1-17.5% WER) are inflated by
benchmark contamination: a vanilla Whisper model self-trained on the ASGDTS test set with zero Swiss German data achieves 13.88% WER, surpassing all published systems. Experiments with Phi-4-
multimodal show an even stronger memorization effect (3.9% WER), revealing that the
benchmark primarily measures convention matching rather than dialectal comprehension. We release two models, a LoRA adapter (25.32% WER, 13.9% cWER) and a full fine-tuned model (25.60% WER, 13.8% cWER), among the few publicly available, honestly evaluated Whisper models for Swiss German, under Apache 2.0 with full reproducibility, requiring no institutional data agreements.
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Computation and Language · Cross-listed from cs.LG
Finer Parameter Steps for Low-Rank PEFT: A Controlled Study with CP Tensor Adapters
Xinjue Wang, Xiuheng Wang, Yejun Zhang et al. (+3 more)
Low-rank adapters are usually compared by sweeping a small set of ranks, but the rank also fixes the resolution of the parameter budget. For a $2048{\times}2048$ OPT
attention projection, increasing LoRA by one rank stores $4096$ trainable scalars, leaving large gaps between feasible low-budget adapter sizes. This paper asks whether a tensorized adapter with finer capacity increments changes the observed accuracy–budget trade-off. We instantiate this question with fixed-component canonical polyadic (CP) tensor adapters. Under a $32{\times}64{\times}32{\times}64$ tensorization, one normalized CP component stores $193$ trainable scalars per projection, about $21$ times smaller than one LoRA rank step. We compare CP adapters and LoRA on OPT-1.3B across SST-2, RTE, and BoolQ under matched target modules, training protocol, data caps, and seed schedules. CP trains stably and fills the gaps between LoRA ranks, but the effect is task-dependent: SST-2 reaches an early low-budget plateau, BoolQ benefits from additional CP components before saturating slightly below LoRA, and RTE remains LoRA-favored. Finer parameter steps are therefore useful for diagnosing PEFT budget sensitivity, but they do not by themselves guarantee a better accuracy–budget curve.
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All authors Xinjue Wang, Xiuheng Wang, Yejun Zhang, Sergiy A. Vorobyov, Esa Ollila, Zhi-Yong Wang
Computation and Language
Masking Stale Observations Helps Search Agents – Until It Doesn't: A Regime Map and Its Mechanism
Haoxiang Zhang, Qixin Xu, Zhuofeng Li et al. (+4 more)
Long-horizon search
agents accumulate large amounts of retrieved content across many tool calls, making context-budget efficiency increasingly important. A minimal intervention is to mask stale observations from the context as the trajectory progresses, but it remains unclear when this form of context management helps and why. We study observation masking through a systematic sweep over various
agent backbones (4B to 284B parameters) and three retrievers on offline and live-web agentic search
benchmarks. We find that the accuracy gain from masking follows an asymmetric inverted-U shape when plotted against the model's accuracy without context management: a plateau under weak retrievers, a peak when a strong retriever meets a mid-capacity model, and a sharp collapse when the model is saturated. This pattern reflects the interaction between retriever recall and the model's implicit filtering capacity, rather than either factor in isolation. Mechanistically, masking implements a
token-for-turn trade-off: it removes observations the model has largely stopped attending to and pages the
agent rarely re-opens. The added turns help when they convert failures into successes, but they fail when masking removes evidence the model would otherwise have used. We therefore reframe context management as a regime-dependent intervention and provide a holistic perspective for analyzing context use in agentic deep search. We release our scaffold and trajectories here (https://github.com/i-DeepSearch/observation-masking) to support future research.
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All authors Haoxiang Zhang, Qixin Xu, Zhuofeng Li, Lei Zhang, Pengcheng Jiang, Yu Zhang, Julian McAuley
Computation and Language · Cross-listed from cs.AI
VESTA: Visual Exploration with Statistical Tool Agents
William Rudman, Abhishek Divekar, Kanishk Jain et al. (+6 more)
Fitting quantitative models to data is a central step in scientific workflows, yet it remains one of the least automated. Recent
agent-based systems leverage
language and
vision-
language models (VLMs) to iteratively propose and refine statistical models, but these systems struggle on more challenging modeling tasks. To address these limitations, we introduce VESTA: Visual Exploration with Statistical Tool
Agents, a framework that equips VLMs with a dynamically growing exploration toolkit to guide model refinement through data transformations, hypothesis-driven visualizations, and robust statistical tests. Unlike prior systems that rely on iterative critique alone, VESTA actively explores data before and during refinement by selecting or creating diagnostic tools, which accumulate in the model's context and can be reused later. We evaluate VESTA against established baselines in three toolkit configurations: no tools, static expert-written tools, and dynamic model-written tools. To support this evaluation, we introduce DAWN (
Dataset for Automated Workflows and Numerical Modeling), a
benchmark targeting distribution fitting and time series modeling with varying difficulty tiers, and culminating in real-world astronomy tasks including modeling initial mass functions and gravitational-wave chirp signals. We find that VESTA's dynamic tool creation outperforms prior agentic pipelines, with the largest gains on complex and domain-specific tasks. We further show that dynamically generated tools are substantially more sophisticated than those produced by existing visual tool-creation systems, covering more diagnostic categories per function and strongly preferring visual outputs that the VLM critic can reason over directly.
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All authors William Rudman, Abhishek Divekar, Kanishk Jain, Sebastian Joseph, Stella S. R. Offner, Matthew Lease, Kyle Mahowald, Greg Durrett, Junyi Jessy Li
Computation and Language · Cross-listed from cs.AI
The Deterministic Horizon: When Extended Reasoning Fails and Tool Delegation Becomes Necessary
Dongxin Guo, Jikun Wu and Siu Ming Yiu
Extended chain-of-thought
reasoning can degrade performance on deterministic state-tracking tasks, not solely because of preference biases but, on the evidence we present, because of information-theoretic limits in the capacity of decoder-only
attention. We present: (1) an
Attention Bottleneck analysis providing evidence that total state-tracking capacity in bits is bounded in terms of head count, head dimension, and context length under stated modeling assumptions, and that total capacity is not the binding constraint; (2) a context-dependent error model with a depth-dependent quadratic term in the error exponent; (3) the State-Space Jaccard metric measuring state drift; and (4) a Deterministic Horizon $d^* \in [19, 31]$ (at $\alpha = 0.5$) marking the depth at which unaided accuracy crosses 50%. Across twelve models and eight task domains (including SWE-Bench, WebArena, and SQL-Multi), tool-integrated
reasoning reaches 76-94% accuracy versus 17-42% for neural chain-of-thought on PermutationProbe. Fine-tuning on optimal-length traces yields $<$3 percentage-point improvement, supporting an architectural ceiling.
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Computation and Language
How Far Do Auto-Interpretation Labels Generalize: A Controlled Study Across Languages, Scripts, and Rewordings
Sripad Karne
Sparse autoencoder (SAE) features are increasingly used to interpret
language models, with auto-generated natural-
language labels serving as the primary interface for understanding what each feature represents. We ask whether these labels generalize: does a feature labeled for a concept actually track that concept across
languages and scripts? Using Serbian digraphia as a controlled testbed – the same
language written in both Latin and Cyrillic via deterministic transliteration – we first find that SAE feature sets activated by the same content in different
languages, scripts, and wordings share substantial overlap (mean Jaccard 0.39 vs 0.13 random baseline, peaking at 0.57), suggesting genuine cross-lingual semantic features. We then test whether auto-interpretation labels keep pace. They often do not: features whose labels describe semantic content miss the same meaning in Serbian up to 4$\times$ more often than within English, and miss Serbian Cyrillic more than Serbian Latin – two scripts that are deterministic transliterations of each other. The gap grows with network depth, yet the labels give no indication that they fail. These results suggest that auto-interpretation labels reflect a feature's behavior on the
languages and scripts a model has seen most in training, rather than the concept itself.
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Computation and Language
Isolating LLM Lexical Bias: A Curation-Free Triangulated Metric for Preference-Stage Learning
Xiaoyang Ming, Jose Hernandez and Thomas Stephan Juzek
Various
language domains have undergone remarkable changes in recent years; these shifts are largely attributed to the advent of Large
Language Models and their misalignment with natural
language usage. These misalignments are thought to partly originate in the preference-learning stage, e.g. Reinforcement Learning from Human Feedback, which generally makes models more useful but simultaneously may introduce systematic lexical bias. In terms of lexical behavior, this is visible in a model's preference for certain formats or the overuse of words (delve, furthermore), even when such patterns are not present in base model outputs. Research on lexical misalignment induced during preference training is constrained by reliance on manual curation. We address this, by introducing the Triangulated Preference Shift score, a metric that triangulates between human gold standards, base models, and instruct variants to isolate shifts induced specifically by preference learning, without manual curation. We provide data across six model families, anchor the results in the literature, and illustrate the general approach's utility by analyzing whether preference learning shifts models toward what could be interpreted as a "
language of prestige". The metric provides an initial automated method to quantify behavioral shifts attributable to preference tuning, and thus, may help inform model
alignment and development of trustworthy AI.
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Computation and Language
Which Institutional Frameworks Do Chatbots Assume? Auditing Jurisdictional Defaults in Multilingual LLMs
Zhizhi Wang and Harini Suresh
LLMs increasingly answer questions about taxes, labor protections, healthcare, education, pensions, and administrative procedures, where usefulness often depends on the applicable jurisdiction.
Multilingual users may write in their most comfortable
language rather than one associated with the country or region whose rules apply. We ask whether deployed LLMs use input
language as a default jurisdictional signal when
prompts omit any country or region. Prior
multilingual audits show that
prompt language can shift cultural, political, or normative outputs; we examine which legal-administrative framework models supply when jurisdiction is underspecified. We evaluate seven LLMs developed in the United States or China on 60 underspecified legal-administrative
prompts in English and Mandarin Chinese under three system-
prompt conditions, yielding 2,520 manually annotated responses. Across models and conditions, Chinese input more often produces China-specific answers, while English input more often produces U.S.-specific, comparative, or generic answers.
Prompts requiring a single answer further increase jurisdiction selection: pooled across models, 74.5% of English-input responses adopt a U.S. framework, while 53.3% of Chinese-input responses adopt a China framework. This directional pattern appears in all seven models. We describe this deployment-level pattern as institutional-framework misselection risk: a fluent answer may rely on a legal-administrative context the user did not intend, especially when their preferred
language differs from the relevant jurisdiction. LLM interfaces should not route institutional advice by input
language alone; when location is absent, they should request it or state the jurisdictional scope of the answer.
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Computation and Language
Bridging Reasoning Trajectories in On-Policy Distillation via Near-Future Guidance
Yuxuan Jiang and Francis Ferraro
On-Policy
Distillation (OPD) improves large
language model
reasoning by training a student model on trajectories sampled from its own policy under teacher supervision. Although OPD operates on trajectories, its learning signal remains
token-level: it identifies deviations through high-loss
tokens and repairs them through local reverse-KL correction. We show that this "trajectory-sampled but
token-learned" mechanism cannot reliably bridge student trajectories toward teacher trajectories. About 30% of high-loss
tokens fall into the low-divergence regime, indicating that many are surface-form mismatches rather than real
reasoning forks. Moreover, even truly divergent
tokens are difficult to repair with isolated
token-level supervision, since
reasoning failures often unfold as short-horizon distributional drift. We propose Trajectory-aware OPD (TOPD), which uses near-future trajectory information to identify real divergent states and distribute guidance across multiple future
tokens. Experiments show that suppressing non-divergent high-loss
tokens improves standard OPD from 47.8% to 48.2% average accuracy, while TOPD further improves performance to 52.2%, with gains on AIME24 from 60.0% to 63.3% and AIME25 from 46.7% to 53.3%.
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Computation and Language
Uncovering Temporal Framing in the News
Tarek Mahmoud, Veronika Solopova, Premtim Sahitaj et al. (+7 more)
Temporal
language does more than place events on a timeline. In news discourse, references to the past, present, and future can function as rhetorical devices that shape interpretation and persuasion. Here, we study temporal framing, defined as the persuasive use of time-related
language to structure meaning rather than to report chronology. We propose a taxonomy of eight temporal frames grounded in prior work on temporality and framing, and we realize it through expert annotation of a
multilingual news corpus. The resulting
dataset includes 458 English and German news articles, with over 2K temporally framed sentences and approximately 3K temporal framing annotations identified from a corpus of more than 20K sentences. We analyze frame prevalence, co-occurrence patterns, and lexical cues, and evaluate temporal framing detection using supervised fine-tuning and zero-shot classification. Our experiments show that temporal framing is learnable at the sentence level, with supervised models substantially outperforming zero-shot approaches. We publicly release the corpus to support future research on temporal framing: https://mbzuai-nlp.github.io/temporal-framing/.
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All authors Tarek Mahmoud, Veronika Solopova, Premtim Sahitaj, Ariana Sahitaj, Max Upravitelev, Mervat Abassy, Hana Fatima Shaikh, Neda Foroutan, Vera Schmitt, Preslav Nakov
Computation and Language
Model-Based Quality Assessment for Massively Multilingual Parallel Data
Abdelaziz M.A. Ibrahim, Zihao Li, Jörg Tiedemann et al. (+1 more)
Large-scale
multilingual bitext often contains two distinct problems: non-parallel sentence pairs and low-quality translations. We decompose model-based assessment for such data into two independent components: parallelism assessment with
multilingual embeddings and reference-free quality estimation (QE). For parallelism, we
benchmark four
embedding models on FLORES-200 and BOUQuET
retrieval tasks, covering 6,654 source–target directions in our target
language-pair inventory. For QE, we evaluate nine reference-free evaluators on professional FLORES-200 translations across 41,412 ordered source–target directions. Results show that no model is universally reliable across translation directions. Naive QE ensembles dilute strong model signals, while documented target-
language coverage is strongly associated with higher QE scores. Overall, these findings suggest that
multilingual parallel-data assessment is best approached as a direction-aware routing and calibration problem, where no single universal metric is expected to suffice across all
languages.
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All authors Abdelaziz M.A. Ibrahim, Zihao Li, Jörg Tiedemann, Shaoxiong Ji
Computation and Language
Specializing Without Forgetting: Analyzing Knowledge Preservation in Multilingual Model Adaptation
Sanchit Ahuja and Terra Blevins
While continual pretraining (CPT) is a practical way to extend large
language models to new
languages, naïve finetuning often erodes existing capabilities through catastrophic forgetting. We investigate which model layers drive this trade-off, and whether interventions at these layers can guide knowledge preservation during adaptation. We interpolate gemma-3-4b model states before and after CPT on five
language families to localize forgetting on reading comprehension and translation, finding that middle-layer reversion yields the largest comprehension recovery, while translation effects vary by
language family and direction. Guided by these findings, we evaluate CPT strategies that leverage this layer information to mitigate forgetting: layer freezing, layer-range L2 regularization, post-hoc layer reversion, and model souping, comparing all strategies against joint
multilingual and family-specific vanilla CPT baselines. We find that preserving the layer weights identified via model interpolation substantially reduces comprehension loss relative to joint CPT, with layer freezing exceeding base model performance on average. However, these strategies yield mixed translation results: dense training or post-hoc reversion often outperforms both training-time constraints and family-specific specialization, complicating prior assumptions about how models should be aligned when extended to new tasks. Instead, we argue that
multilingual adaptation strategy should be informed by target
language, base model knowledge, and downstream task, and propose interpolation-based localization as a diagnostic for identifying candidate layers before committing to a training-time intervention in a new setting.
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Computation and Language · Cross-listed from cs.AI
On Wednesdays, We Ask Questions: Optimizing "Active Listening" in Automated Legal Triage and Referral
Quinten Steenhuis and Jacqueline Harvey
The FETCH classifier generates follow-up questions to help refine the best match for the applicant's legal problem, using a low-cost ensemble of LLMs. In this paper, we describe an expert attorney and LLM-assisted evaluation of the follow-up question approach in FETCH and show that while low-cost LLMs perform well at classification tasks, generating high-quality plain-
language questions in this setting appears to require a more sophisticated and higher-cost model. Through discussion with legal intake workers, we propose a rubric for the evaluation of legal intake classification questions, and we find that
prompt engineering alone is not enough to improve question quality for intake purposes. We also find that LLM-as-judge and human ratings diverge. We demonstrate that with the addition of a single high-cost model, GPT-5, the classifier can elicit relevant information from applicants for legal help, and that the questions lead to more accurate performance at classification tasks. We also find uneven fact elicitation across different categories, including domestic violence, at odds with family law screening protocols, suggesting the value of including dedicated screening panels for certain areas of law.
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Computation and Language
Effects of Varying LLM Access on Essay Writing Behavior
Julia Christenson, Karin de Langis, Shirley Anugrah Hayati et al. (+1 more)
Investigating the degree to which large
language models (LLMs) affect teaching and learning in universities can help identify strategies for integrating LLMs in a way that supports, rather than undermines, student learning outcomes. This study examined how varying levels of LLM assistance affect writing performance, engagement, and perceived authorship. We report a pilot study in which 24 college students were randomly assigned to write a short essay with no LLM access, limited access (<=3
prompts, responses capped at 100 words), or unlimited access. Overall essay quality was statistically indistinguishable across groups. Yet writing behavior and perceived authorship diverged sharply: students with limited access reported higher ownership (62.5% would submit the essay as independent work, vs. 25% in the unlimited group), stronger organizational gains, and more strategic, revision-focused prompting. The unlimited group spent more time writing, produced essays more similar to LLM output, and reported reduced creative expression. Our findings suggest that constraining, rather than banning, LLM access may preserve authorship confidence while retaining the scaffolding benefits of AI assistance.
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All authors Julia Christenson, Karin de Langis, Shirley Anugrah Hayati, Dongyeop Kang
Computation and Language
DeSQ: Decomposition-based SPARQL Query Generation
Papa Abdou Karim Karou Diallo, Aditya Sharma, Neshat Elhami Fard et al. (+1 more)
Dominant approaches to Knowledge Base Question Answering (KBQA) fall into two categories. First is the generation of a formal query that suffers from brittleness and limited explainability, and the second is direct answer
retrieval through KB exploration that is computationally costly and prone to
hallucination. To combine the strengths of both paradigms while mitigating their respective weaknesses, we introduce DeSQ (Decomposition-based SPARQL Query Generation), a KB-agnostic framework that operates in three stages. First, it decomposes complex questions into Atomic Constraints (ACs) that mirror the relational structure of the underlying KB. Second, it generates a two-part structured output: (a) Mapping of each AC to its corresponding SPARQL Fragment, using standardized variable and URIs placeholders, and (b) URIs Grounding block describing each placeholder. Third, it assembles these fragments into a complete SPARQL query. DeSQ surpasses state-of-the-art approaches on four out of five major
benchmarks and demonstrates superior robustness to lexical variation. Beyond performance gains, our framework greatly simplifies evaluation by eliminating the need for a live KB endpoint, and its structured output enables fine-grained error analysis, allowing more targeted interventions for improvement.
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All authors Papa Abdou Karim Karou Diallo, Aditya Sharma, Neshat Elhami Fard, Amal Zouaq
Computation and Language · Cross-listed from cs.LG
BAGEN: Are LLM Agents Budget-Aware?
Yuxiang Lin, Zihan Wang, Mengyang Liu et al. (+9 more)
While
agents are increasingly spending more resources, today
agent cost is mostly measured only after execution. A Budget-Aware
Agent (BAGEN) should treat budget as an active control signal, rather than a passive cost metric. We first systematically define budget estimation as internal budgets (from
agent computation) and external budgets (from
agent actions). We then formalize budget-awareness as progressive interval estimation: at each step of a plan, an
agent should predict an upper and lower bound on remaining budget, and alert when completion is unlikely. Scoring with a rollout-replay protocol, we find consistent failure patterns on four environments and five frontier
agents: (1) strong
agents do not necessarily have strong budget-awareness, with correlation r=0.35. (2) frontier models are consistently over-optimistic, continue spending on tasks that are unlikely to succeed, instead of alerting the user early. (3) budget-aware signal is actionable and trainable. Early stop saves 28-64%
tokens on failed trajectories, and SFT+RL strengthens early stop and alert behavior. (4) precise interval calibration remains challenging, with interval coverage capping at 47% after SFT+RL. Project page: https://ragen-ai.github.io/bagen/
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All authors Yuxiang Lin, Zihan Wang, Mengyang Liu, Yuxuan Shan, Longju Bai, Junyao Zhang, Xing Jin, Boshan Chen, Jinyan Su, Xingyao Wang, Jiaxin Pei, Manling Li
Computation and Language
BOUTEF: A Multilingual Corpus for FakeNews in North Africa – Language as a Weapon
Kamel Smaili, Yassine Toughrai, Amina Laggoun et al. (+1 more)
The rapid spread of fake news on social media has become a major challenge, particularly in
multilingual and under-resourced contexts such as North Africa. In this paper, we introduce BOUTEF, a large-scale
multilingual corpus designed to study the propagation, characteristics, and impact of fake news in Algeria and Tunisia. The corpus integrates three complementary components: fake narratives, genuine narratives, and associated user-generated comments, along with verified debunking information. It covers a wide range of
languages and linguistic varieties, including MSA, Algerian and Tunisian dialects, Arabizi, French, English, and code-switched
language. Building on this resource, we conduct a comprehensive empirical analysis combining quantitative and qualitative approaches. We examine thematic distributions, linguistic and rhetorical strategies, sentiment patterns, and social engagement dynamics. Statistical analyses reveal significant associations between thematic categories and message veracity, as well as strong correlations between user engagement and the visibility of fake content. Our findings show that fake news relies heavily on emotionally charged narratives, sensational framing, and hybrid linguistic practices that enhance virality and audience engagement. In contrast, debunking content adopts a more factual and verification-oriented style. Furthermore, a comparative analysis between Algeria and Tunisia highlights both shared dynamics and country-specific characteristics shaped by sociopolitical contexts. The results emphasize the role of informal
language practices in the
diffusion and reception of misinformation. By providing a rich, annotated, and publicly available
dataset, this work contributes to advancing research on fake news detection, low-resource
language processing, and the understanding of information disorders in complex linguistic environments.
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All authors Kamel Smaili, Yassine Toughrai, Amina Laggoun, David Langlois
Computation and Language
RealityTest: How People Probe AI Identity and Whether Models Disclose It
Anna Gausen, Sarenne Wallbridge, Bessie O'Dell et al. (+2 more)
AI systems are increasingly deployed in conversational settings where users may be uncertain whether they are speaking with a human or an AI. Despite mounting regulatory
attention to this known safety risk, existing evaluations of AI disclosure are typically English-only, based on machine-generated questions, and restricted to text. We present RealityTest to comprehensively test whether AI systems disclose their identity when asked. The
benchmark is the first large-scale
multimodal and
multilingual evaluation, grounded in human data on how people actually encounter and question AI identity in the real-world. Alongside the
benchmark, we release the underlying
dataset of 3,152 identity-probing queries collected from ~750 participants across 49 countries and five
languages, in text and
speech scenarios. We find that only 31% of people ask about identity directly in ambiguous scenarios, and that the questions people ask are far more diverse than machine-generated queries. We test 17 text and 6
speech models, and find substantial variation in disclosure behaviour. However, a single suppression instruction reduces disclosure rates to below 30%, even in the best-performing models. Validating our investment in diverse, human-grounded evaluation data, we find that how the question is phrased and the context of the conversation matter more for disclosure than which model is being tested. Safety evaluations built on narrow or synthetic query sets risk mischaracterising how models behave in realistic deployment settings.
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All authors Anna Gausen, Sarenne Wallbridge, Bessie O'Dell, Christopher Summerfield, Hannah Rose Kirk
Computation and Language · Cross-listed from cs.CR
DataShield: Safety-degrading Data Filtering for LLM Benign Instruction Fine-Tuning
Junbo Zhang, Qianli Zhou, Xinyang Deng et al. (+3 more)
Large
language models (LLMs) suffer from degraded safety capabilities even when fine-tuned with benign
datasets. However, existing methods for identifying safety-degrading samples in benign
datasets suffer from high computational costs and significant noise issues. In this paper, we propose DataShield to efficiently and effectively identify potential safety-degrading samples. Our key intuition is based on the observation that benign fine-tuning increases the overall response compliance of LLMs. DataShield's key technical insight is to quantify each sample's contribution to the model's compliance behavior as its safety degradation score. DataShield consists of three core components: (1) Compliance Vector Extraction, which captures the LLM's compliance behavior tendency; (2) a novel Compliance-Aware Score (CAS), which automatically identifies the optimal safety-critical layer; and (3) Safety-degrading Sample Filtering, which quantifies the projection shift of training data along the compliance direction. Extensive experimental evaluation on Llama3-8B, Llama3.1-8B, and Qwen2.5-7B using the Alpaca and Dolly benign
datasets validates our method's effectiveness in identifying high-risk and low-risk data subsets. We also observe that open-ended question answering is more likely to trigger safety degradation, and corresponding responses tend to be longer. We hope this work can provide new insights into data-centric defense methods. The source code is available at: https://github.com/ZJunBo/DataShield.
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All authors Junbo Zhang, Qianli Zhou, Xinyang Deng, Wen Jiang, Jie Pan, Jinbiao Zhu
Computation and Language
Language Models Learn Constructional Semantics, Not To Mention Syntax: Investigating LM Understanding of Paired-Focus Constructions
Wesley Scivetti, Ethan Wilcox, Nathan Schneider et al. (+2 more)
Grasping the semantics of rare constructions (form-meaning pairings) has been shown to be a challenging problem that has currently only been solved by the largest LLMs. It remains an open question if open-source models have robust constructional understanding, and if so, what learning dynamics underlie the acquisition of this knowledge. Focusing on a set of rare Paired-Focus constructions in English (e.g. "let alone", "much less"), we construct a novel
dataset to test their meanings using both scalar adjectival semantics and general world knowledge. Testing a wide range of models differing in parameter count, architecture, and pretraining
dataset size, we find that several modestly sized models are sensitive to both the forms and the meanings of Paired-Focus constructions, though models trained on human-scale data fail at all meaning evaluations. Turning to training dynamics for a set of open-checkpoint models, we find that Paired-Focus understanding emerges later in training than Paired-Focus syntactic knowledge, and that learning of Paired-Focus semantics is correlated with gains in some domains of world knowledge. Overall, our empirical results support the conclusion that modestly sized open-source models can grasp the rare Paired-Focus constructions, and demonstrate a connection between knowledge of Paired-Focus constructions and other meaning domains.
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All authors Wesley Scivetti, Ethan Wilcox, Nathan Schneider, Kanishka Misra, Leonie Weissweiler
Computation and Language
LongTraceRL: Learning Long-Context Reasoning from Search Agent Trajectories with Rubric Rewards
Nianyi Lin, Jiajie Zhang, Lei Hou et al. (+1 more)
Long-context
reasoning remains a central challenge for large
language models, which often fail to locate and integrate key information in extensive distracting content. Reinforcement learning with verifiable rewards (RLVR) has shown promise for this task, yet existing methods are limited by low-confusability distractors and sparse, outcome-only reward signals that cannot supervise intermediate
reasoning steps. To address these issues, we introduce LongTraceRL. For data construction, we generate multi-hop questions via knowledge graph random walks and leverage search
agent trajectories to build tiered distractors: documents the
agent read but did not cite (high confusability) and documents that appeared in search results but were never opened (low confusability), producing training contexts that are far more challenging than those built by random sampling or one-shot search. For reward design, we propose a rubric reward that uses the gold entities along each
reasoning chain as fine-grained, entity-level process supervision. This rubric reward is applied only to responses with correct final answers (positive-only strategy), distinguishing the
reasoning quality among correct responses and preventing reward hacking. Experiments on three
reasoning LLMs (4B–30B) across five long-context
benchmarks demonstrate that LongTraceRL consistently outperforms strong baselines and encourages comprehensive, evidence-grounded
reasoning. Codes,
datasets and models are available at \href{https://github.com/THU-KEG/LongTraceRL}{https://github.com/THU-KEG/LongTraceRL}.
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All authors Nianyi Lin, Jiajie Zhang, Lei Hou, Juanzi Li
Computation and Language
What Gets Unmasked First? Trajectory Analysis of Diffusion Models for Graph-to-Text Generation
Qing Wang, Jacob Devasier and Chengkai Li
We present the first systematic study of masked
diffusion language models (MDLMs) for graph-to-text generation. We analyze MDLM generation trajectories – the order in which
tokens are unmasked during iterative decoding – and find that, unlike autoregressive LLMs which generate text linearly, MDLMs naturally prioritize entities first, followed by relational and function words, with structural
tokens resolved last. We further identify a previously undocumented failure mode of supervised fine-tuning: SFT disrupts this strategy by prematurely anchoring structural sentence-ending
tokens early in the decoding trajectory, effectively fixing the output length which can lead to omitted or hallucinated information. To address this, we propose lambda-scaled structural decoding, a training-free inference-time modification that downweights structural
token confidence and recovers +9.4 BLEU-4. Finally, we introduce Graph-LLaDA, which integrates a Graph
Transformer encoder into LLaDA's decoding process to explicitly incorporate relational graph structure. Cross-
dataset evaluation on LAGRANGE reveals that previous baselines overfit to
dataset-specific patterns, while LLM- and MDLM-based approaches generalize significantly better.
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Computation and Language
Disagreeing Rationales: Rethinking Classification and Explainability Evaluation in Hate Speech Detection
Benedetta Muscato, Beiduo Chen, Gizem Gezici et al. (+2 more)
Human disagreement is ubiquitous and well-known in labeling. However, variation in explanations, captured through
token-level human rationales, remains far less explored. At the same time, it is unclear how to best evaluate human labels and rationales – or even how to best aggregate rationales beyond majority vote – in light of this variation. Yet, rationales may provide additional insights into the richness of human
reasoning, that may differ in style, values and interpretations – especially in subjective NLP tasks like hate
speech detection. In this work, we unify diverse models, training strategies, loss functions, and existing evaluation metrics under a single protocol by systematically re-implementing them across different label and rationale representation spaces. Classification metrics are organized around two key properties – predictive and distributional – while explainability metrics through three complementary dimensions: plausibility, faithfulness, and complexity. In this unified supervision framework, we evaluate model behavior across classification and explainability metrics, as well as metric sensitivity to the choice of label (hard and soft) and rationale representation space (hard, intermediate and soft). Results show that both hard and soft metrics favor softer representations, highlighting their effectiveness in capturing variation and the need to rethink evaluation in subjective NLP.
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All authors Benedetta Muscato, Beiduo Chen, Gizem Gezici, Barbara Plank, Fosca Giannotti
Computation and Language
What Am I Missing? Question-Answering as Hidden State Probing
Chu Fei Luo, Samuel Dahan and Xiaodan Zhu
Test-time
reasoning has become a significant field of study since the introduction of chain-of-thought
reasoning in large
language models (LLMs). However, the mechanisms of this
reasoning process are still under-explored – from the same input
prompt, and even the same partial solution, LLMs can produce varied answers if sampled multiple times. We propose to leverage question-asking as an inference-time intervention that articulates information about the model's hidden state. To achieve that, we present a student-teacher setting where a student asks questions to a teacher. We train a probe on the student's hidden state before and after asking a question and find it is predictive of the trajectory's final correctness, even before generating the teacher's answer. This suggests there is a meaningful signal from the self-diagnosis that occurs during question generation rather than information transfer from the teacher. We then frame question-asking as a sequential decision problem, using this probe as a quality score, and define a gating policy to ask questions that maximize likelihood of correctness. We find that the success of question-asking as an intervention is largely dependent on the model's self-consistency. Our empirical results show a gap between detection and recovery; while our gating policy captures model correctness and uncertainty, interventions are equally likely to harm correct trajectories as they are to recover incorrect ones. This gap between diagnosis and correction has broader implications on
language models' capacity for self-refinement under uncertainty.
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Computation and Language · Cross-listed from cs.CV
Vision-Language Models Suppress Female Representations Under Ambiguous Input
Arnau Marin-Llobet, Simon Henniger and Mahzarin R. Banaji
Alignment teaches
vision-
language models (VLMs) to avoid expressing demographic biases, and when gender is clearly visible they largely succeed. Far less is known about ambiguous inputs (a worker in full gear, a figure seen from behind), cases common in practice yet rarely studied. We find that minimal prompting pressure exposes occupation-gender defaults when prompting ambiguous input images, with models collapsing to male even for strongly female-stereotyped occupations. But do these outputs reflect what models actually encode internally? We introduce LALS (Latent Association Leaning Score), a zero-shot metric that projects visual-
token activations into the model's text-
embedding space to measure concept associations per
token and layer. Across 15 occupations, over 800 gender-ambiguous images, and four VLMs, internal representations and outputs often become systematically decoupled: models often encode a female association internally yet output male. Layer-wise analysis reveals an asymmetric filter: male signal amplifies end-to-end while female signal peaks mid-network and is suppressed before generation. A color ablation shows that culturally loaded visual cues such as clothing color further modulate these internal associations.
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Computation and Language
Semantic Triplet Restoration: A Novel Protocol for Hierarchical Table Understanding in Large Language Models
Yibin Zhao, Fangxin Shang, Dingrui Yang et al. (+1 more)
Table question answering requires models to recover semantic relations encoded implicitly by two-dimensional layout, merged
cells, and hierarchical headers. Current pipelines typically use HTML or Markdown as intermediate table representations, but these layout-oriented serializations introduce markup overhead and require large
language models to infer header-
cell alignments from row and column spans. We propose Semantic Triplet Restoration (STR), a protocol that rewrites each
cell as an atomic fact <item path, feature path, value>, where the item path specifies the row-wise entity, the feature path specifies the hierarchical attribute, and the value contains the
cell content. We also present TripletQL, a lightweight query-aware router that uses STR to select an appropriate rendering or filtered subset of triplets for each question. Across four Chinese and English table-QA
benchmarks, STR matches or improves upon HTML-based baselines while reducing input
tokens. The relative benefit grows for smaller
language models and longer table contexts, suggesting that explicit semantic representations are especially useful under constrained inference budgets. Code and data are available at https://github.com/Phoenix-ni/STR.git .
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All authors Yibin Zhao, Fangxin Shang, Dingrui Yang, Yuqi Wang
Computation and Language
Preference-Aware Rubric Learning for Personalized Evaluation
Yilun Qiu, Xiaoyan Zhao, Yang Zhang et al. (+7 more)
As Large
Language Models (LLMs) evolve from general-purpose assistants to user-centric
agents, personalization has become central to aligning model behavior with individual preferences, making the evaluation of personalized
alignment a critical bottleneck. Existing evaluation methods-ranging from automatic metrics to LLM-as-a-judge approaches-fail to capture subjective, user-specific preferences embedded in long-term interaction histories. We identify three essential principles for reliable and effective personalized evaluation: Representativeness, User-Consistency, and Discriminativeness. To address these principles, we introduce Personalized Evaluation as Learning, a paradigm that formulates personalized evaluation as a learning problem rather than a static judgment. Under this paradigm, we propose PARL (Preference-Aware Rubric Learning for Personalized Evaluation), a framework that learns to induce preference-aware evaluation rubrics directly from raw user histories and performs a self-validation mechanism to ensure consistency with the user's preferences. PARL integrates rubric induction with a discriminative reinforcement learning objective that contrasts user-authored responses against competitive personalized model outputs, enabling the learned rubrics to capture precise, user-specific decision boundaries. Experiments on real-world personalized text generation tasks show that PARL consistently induces high-fidelity rubrics that reliably identify user-aligned responses and generalize across users and tasks, while capturing stable stylistic preferences and fine-grained evaluative patterns. To ensure reproducibility, our code is available at https://github.com/SnowCharmQ/PARL.
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All authors Yilun Qiu, Xiaoyan Zhao, Yang Zhang, Yuxin Chen, Cilin Yan, Jiayin Cai, Xiaolong Jiang, Yao Hu, Yoko Yamakata, Tat-Seng Chua
Computation and Language
UniAudio-Token: Empowering Semantic Speech Tokenizers with General Audio Perception
Yuhan Song, Linhao Zhang, Aiwei Liu et al. (+6 more)
Semantic
speech tokenizers have become a widely used interface for Audio-LLMs, owing to their compact single-codebook design and strong linguistic
alignment. However, their focus on linguistic abstraction induces acoustic blindness, limiting their applicability beyond
speech-centric tasks. We propose UniAudio-
Token, a framework that empowers semantic tokenizers with general audio perception without compromising
speech ability. Instead of altering the semantic paradigm, UniAudio-
Token mitigates its information loss through two key innovations: (1) Semantic-Acoustic Primitives (SAP) provide structured supervision by decomposing audio into linguistic content, vocal attributes, and auditory-scene primitives; and (2) Semantic-Acoustic
Equilibrium (SAE) introduces a content-aware gating mechanism that adaptively restores fine-grained acoustic details from shallow layers. Extensive evaluations show that UniAudio-
Token learns comprehensive universal representations while preserving high-fidelity
speech generation. When integrated with downstream LLMs, it outperforms all single-codebook baseline tokenizers on both understanding and generation tasks, effectively serving as a unified audio interface. We publicly release all our code, including training and inference scripts, together with the model checkpoints at https://github.com/Tencent/Universal_Audio_Tokenizer.
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All authors Yuhan Song, Linhao Zhang, Aiwei Liu, Chuhan Wu, Sijun Zhang, Wei Jia, Yuan Liu, Houfeng Wang, Xiao Zhou
Computation and Language
If LLMs Have Human-Like Attributes, Then So Does Age of Empires II
Adrian de Wynter
Much research has been carried out on large
language models (LLMs) and LLM-powered agentic workflows. However, many works within the field state emergence of, ascribe to, or assume, generalised anthropomorphic attributes to them (e.g., morality or understanding of natural
language). Our goal is not to argue in favour or against the existence of these attributes, but to point out that these conclusions could be incorrect. For this we build and train a simple neural network on the videogame Age of Empires II, and note that any entity in a sufficiently-powerful substrate, such as LEGO or the Greater Boston Area, could also present such attributes. Hence, the purported anthropomorphic attributes of LLMs are empirically non-unique: although some properties (e.g., responses to
prompts) could remain invariant, others, such as the interpretation of their perceived behaviour, might change with the substrate. Thus, any empirically-grounded discussion on these attributes requires explicit measurement criteria; otherwise the interpretation is left to the representation. We then show that assuming that these attributes exist or not in a system, independent of the substrate and in a generalised way, leads to either circular or uninformative conclusions. This is regardless of the experimenter's viewpoint on the subject, or whether the outcome shows existence or non-existence. Finally we propose a 'null' assumption, where one assumes LLM non-uniqueness instead of assuming anthropomorphic attributes to set up an experiment, along with examples of it. We also discuss potential objections to our work, briefly survey the field, and prove that Age of Empires II is functionally- and Turing-complete.
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Computation and Language
Reliable Multilingual Orthopedic Decision Support from Clinical Narratives: Language-Aware Adaptation and Verification-Guided Deferral
Danish Ali, Li Xiaojian, Sundas Iqbal et al. (+1 more)
Multilingual orthopedic decision support remains challenging in low-resource healthcare settings, where clinical narratives contain specialized terminology, mixed scripts, incomplete evidence, label imbalance and
language-dependent documentation patterns. This article presents a reliability-oriented framework for classifying free-text orthopedic notes in English, Hindi and Punjabi. We compare task-aligned
multilingual transformer encoders, a task-fine-tuned DistilBERT baseline, zero-shot instruction-tuned large
language models (LLMs) and a domain-adaptive encoder, IndicBERT-HPA. IndicBERT-HPA augments IndicBERT with
language-aware orthopedic adapter heads to support clinically relevant
multilingual representation learning. Evaluation extends beyond aggregate accuracy to per-class performance, ROC-AUC, AUPRC, expected calibration error, cross-
language stability and robustness under controlled balanced and natural-prevalence distributions. The evaluated zero-shot LLMs remain substantially less effective than task-adapted encoders for closed-set classification, with
language-dependent instability. Under natural clinical prevalence, IndicBERT-HPA achieves the strongest overall performance, reaching an averaged Macro-F1 of 0.8792, Macro-AUROC of 0.894 and AUPRC of 0.902. We further implement a deterministic selective-verification layer combining confidence gating, evidence-consistency checking and
language-risk screening. On a randomly selected held-out 5,000-record subset, it achieves 84.4% selective accuracy and 0.76 selective Macro-F1 at 72.3% coverage, compared with 71.5% accuracy and 0.65 Macro-F1 for accept-all prediction. These results support reliability-oriented
multilingual clinical decision support with explicit deferral.
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All authors Danish Ali, Li Xiaojian, Sundas Iqbal, Farrukh Zaidi