Computation and Language · Cross-listed from cs.AI
Capacity, Not Format: Rethinking Structured Reasoning Failures
Hengxin Fan
Prior work treats structured output as a
reasoning tax, but this framing is incomplete: the cost of formatting depends strongly on a model's spare capacity. Using information-matched prose controls and a four-level schema complexity gradient, we separate format-specific effects from
prompt-length confounds across 4 models and 5
benchmarks with 0% parse failures on successfully generated responses. We find that structured formats are capacity-dependent. Models with sufficient headroom absorb JSON constraints without degradation (Sonnet: $88.7\pm4.0$% JSON vs. $89.3\pm1.7$% CoT on MATH-Hard). In contrast, formats severely degrade models operating near their limits through two distinct mechanisms. First, under standard
token budgets, Haiku drops 36.2pp ($p < 0.0001$) largely due to truncation. Second, even with extended budgets eliminating truncation, GPT-4o-mini drops 28.0pp ($p < 0.001$), revealing pure capacity competition independent of
token exhaustion. This format penalty scales with schema complexity (McNemar $p < 0.0001$) and cannot be explained by
prompt length alone. Furthermore, these results qualify claims of frontier model immunity: on AIME competition math, Opus 4.7 drops from 96.2% to 91.0% under JSON ($-5.3$pp; the displayed percentages are independently rounded, exact difference is $7/133 = 5.26$pp $\approx 5.3$pp). A delayed-structure ablation –
reasoning freely before formatting – recovers most of the lost accuracy (3-run mean: 80–87%), supporting the capacity competition mechanism. The practical implication is not to avoid structured output, but to match it to capacity: when a model is near its limits, think first, format later.
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Computation and Language · Cross-listed from cs.AI
Correct Looks Better: Pairwise Comparisons Reveal Accuracy Rankings
Mina Remeli and Moritz Hardt
Pairwise comparisons combined with aggregation methods like Elo have become central to evaluating generative models, yet concerns remain that they reward superficial stylistic cues or display judge biases. In a more positive turn, we show that model rankings from pairwise comparisons strongly agree with ground-truth-based accuracy rankings when such ground truth is available for comparison. By converting five well-known
benchmarks into free-form generative evaluations, we find that Elo rankings achieve a Spearman correlation above 0.9 with accuracy rankings and substantially outperform direct evaluation when the judge is weak. Furthermore, style and judge bias have only minor effects on model rankings, despite most judgments occurring on pairs where both candidate answers are correct (or incorrect). On such pairs, we find that repetition after the final answer (echo) is a causal driver of judge preference.
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Computation and Language
Introducing multiplex semantic networks as multifaceted representations of creative associative knowledge across multilingual samples
Edith Haim, Kurt Haim, Roger E. Beaty et al. (+2 more)
Creativity is a complex cognitive ability that relies on knowledge organisation and
retrieval from semantic
memory. Yet most research uses a single task to measure it, capturing only a fraction of this complexity. This study investigates multiplex networks - layered semantic networks obtained from six cognitive tasks - as a more comprehensive approach to modelling the associative knowledge underlying creativity. We collected data from N=518 individuals from four countries (Austria, USA, Singapore, Italy). From their responses to verbal fluency, sentence-chain, free association, and narrative writing tasks, we constructed semantic networks and assembled them in a multiplex structure. AI persona-based responses provided a comparison baseline. Structural reducibility analyses showed that different task layers captured distinct, non-redundant information about semantic organisation, supporting the use of multiple tasks over any single one. The networks from high- and low-creative groups remained structurally distinct, while AI-generated networks showed near-identical structures regardless of creativity group. Finally, we used 12 features (network measures, emotional scores, and spreading activation simulations) in a machine learning model using ridge regression to predict individual creativity scores. The combination of structurally similar layers, as identified in the previous stage, improved a proof-of-concept prediction accuracy by 50%. Structural measures showed the highest feature importance, with spreading activation dynamics providing additional predictive power. Together, these findings indicate that multiplex semantic networks capture a richer, cross-cultural picture of associative knowledge underlying creativity. We also release our diverse
dataset and code to foster diverse computational approaches within the creativity community.
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All authors Edith Haim, Kurt Haim, Roger E. Beaty, Cynthia S.Q. Siew, Massimo Stella
Computation and Language
PriFT: Guiding Supervised Fine-Tuning with Pretrained Priors
Ke Wang, Shuangqi Li, Mathieu Salzmann et al. (+1 more)
Supervised fine-tuning (SFT) is an efficient approach for downstream task adaptation and often serves as the initialization stage for reinforcement learning (RL), but it can show weaker generalization than RL. A key limitation is its off-policy objective: SFT fits fixed demonstrations
token by
token, including targets poorly aligned with the model's pretrained distribution, which can lead to overfitting. A recent line of work addresses this issue by assigning larger training weights to
tokens better aligned with the current model's predictive distribution, with the intuition that fitting these
tokens are less distortive to the model's knowledge and representations. However, computing the
token weights from the model that is currently fine-tuned entangles
token weights with the optimization trajectory, inducing a self-reinforcing loop which concentrates the supervision signal to a narrow set of initially preferred
tokens. To address this, we propose PriFT (Prior-support guided Fine-Tuning), which derives
token weights from a frozen pretrained reference to obtain a stable reweighting signal unaffected by fine-tuning. This signal estimates prior support: the extent to which each target
token is supported by the pretrained distribution. By reweighting
tokens according to their prior support, PriFT limits excessive adaptation to targets requiring substantial deviation from the pretrained distribution and improves SFT generalization. We introduce two instantiations: PriFT-prob uses pretrained target-
token probability, while PriFT-mass selects
tokens by cumulative probability mass under the pretrained distribution. Across mathematical
reasoning, code generation, and medical QA, PriFT achieves state-of-the-art results among SFT baselines, while also providing a stronger initialization for subsequent RL.
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All authors Ke Wang, Shuangqi Li, Mathieu Salzmann, Pascal Frossard
Computation and Language
LexRubric: A Rubric-Guided Diagnostic Benchmark for Open-Ended Legal Tasks
Yifan Chen, Haitao Li, Yiran Hu et al. (+6 more)
As large
language models (LLMs) are increasingly applied to real-world legal tasks, evaluating the reliability of their open-ended legal responses has become essential. These tasks require context-sensitive answers and allow little room for error, motivating fine-grained and diagnostic evaluation that can identify specific sources of response quality failures. We introduce LexRubric, a rubric-based
benchmark for evaluating open-ended Chinese legal tasks. LexRubric contains 649 instances from legal consultation and judicial examination, which reflect both everyday legal needs and professional legal
reasoning and cover 14 legal scenarios. It further includes 12,337 expert-written atomic scoring criteria organized under a unified six-dimensional framework, enabling accurate evaluation and diagnostic analysis across tasks and evaluation dimensions. To validate the reliability of the evaluation, we test multiple judge models and compare model-based judgments with human judgments. We further evaluate 18 recent general and legal-domain LLMs on LexRubric. Results show that different models exhibit distinct capability profiles, and that open-ended legal tasks remain challenging for current LLMs. Data is available at: https://github.com/foggpoy/LexRubric.
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All authors Yifan Chen, Haitao Li, Yiran Hu, Kaisong Song, Jun Lin, Yueyue Wu, Qingyao Ai, Min Zhang, Yiqun Liu
Computation and Language · Cross-listed from cs.LG
Reasoning Arena: Trace Tournaments When Verifiable Rewards Fall Short
Han Zhou, Adam X. Yang, Laurence Aitchison et al. (+2 more)
Reinforcement learning with verifiable rewards (RLVR) has become a leading paradigm for improving the
reasoning ability of large
language models through outcome-based supervision. However, verifiable rewards frequently become uninformative at the group level: when all sampled traces of a given
prompt receive identical rewards, group-relative advantage estimation provides no gradient signal, even though the traces may differ substantially in
reasoning quality. We propose
Reasoning Arena, an adaptive training framework that routes such non-diverse reward groups to a judge system instead of discarding them. Beyond examining the final answer,
Reasoning Arena constructs trace tournaments, where
reasoning traces are compared head-to-head to expose finer-grained preferences within the group, converting
reasoning quality into rich relative reward signals. To make reward estimation efficient, rather than exhaustively comparing every pair, each new trace is evaluated against a small, dynamically updated pool of previously generated traces as anchors to efficiently establish a relative ranking. We then fit a Bradley-Terry model on the incomplete comparison graph, enabling scalable RL integration without quadratic pairwise comparisons. Empirical results demonstrate that
Reasoning Arena consistently outperforms the RLVR baseline by 7.6% on average in competition mathematics and coding
benchmarks. By converting otherwise wasted zero-advantage samples into useful gradient updates, our method accelerates training by 27% to 41%, saving nearly 50% of generation compute, and substantially improves overall
reasoning performance.
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All authors Han Zhou, Adam X. Yang, Laurence Aitchison, Anna Korhonen, Albert Q. Jiang
Computation and Language
Precision Is Not Faithfulness: Coverage-Aware Evaluation of Grounded Generation with a Complete Oracle
Juan S. Santillana
Reference-free faithfulness metrics verify each atomic claim a model makes against ground truth, and are increasingly used to evaluate grounded generation. We show they share a blind spot: they measure only precision – are the stated claims supported? – and therefore reward abstention, since a model can score near-perfect faithfulness by saying almost nothing. We make this measurable using Formula 1 telemetry, a domain where strategic ground truth is derived deterministically and, crucially, completely: for each decision we know the full set of facts that mattered. This completeness – absent in open-domain faithfulness
benchmarks – lets us measure recall (coverage of the relevant facts) exactly, alongside precision. On a
multilingual (EN/ES/PT)
benchmark of 7,253 decision instances spanning 157 races, the most precise frontier model covers under half of the relevant facts and ranks last by F1, so requiring coverage reorders the systems; the same effect reappears in a second complete-oracle domain (NOAA weather forecasts). Fine-tuning small models (1B-7B) on the complete oracle closes the precision-recall gap entirely (F1 ~0.98), beating every zero-shot frontier system regardless of scale. We pair faithfulness with coverage into a single score, validate the metric (controlled perturbation; agreement across a model-free regex extractor and a cross-family LLM extractor, system-level Spearman 1.0), and give a verifier-guided generation method that improves precision and recall without references. We release the
benchmark, structured annotations, metric, baselines, and an interactive demo.
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Computation and Language
Is Text All You Need? Text as a Universal Information Bottleneck for Speech LLMs
Ming-Hao Hsu, Yuxuan Hu, Shujie Liu et al. (+3 more)
Large
language models (LLMs) provide a powerful
reasoning backbone for
speech understanding, but integrating continuous acoustic signals into a pretrained LLM remains challenging. A central design question is how to tie
speech representations to the LLM's text input space while preserving the continuous variation needed for different
speech tasks. In this work, we propose Convex Gate (C-Gate), a
speech-LLM bridge that represents each frame as a convex combination of frozen
token embeddings. This architectural convex-hull constraint fixes the output codebook while allowing continuous mixtures learned from task supervision. With a Whisper-large-v3 encoder, a partially adapted Qwen2.5-7B-Instruct decoder, and joint training on
speech recognition,
emotion recognition, and spoken
reasoning, C-Gate performs accurate transcription and
emotion recognition, our representative semantic and acoustic tasks, through one shared decoder. On text-only
benchmarks, the adapted decoder loses instruction-following and MMLU accuracy and matches or exceeds the original model on GSM8K and HellaSwag. We further design analyses and interventions on the trained model to examine where the bridge sequence carries task information and how the decoder reads it. These findings show how fixed text
embeddings can support both semantic and acoustic readouts through continuous
speech-conditioned mixtures.
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All authors Ming-Hao Hsu, Yuxuan Hu, Shujie Liu, Jinyu Li, Yan Lu, Zhizheng Wu
Computation and Language · Cross-listed from cs.AI
Experience Makes Skillful: Enabling Generalizable Medical Agent Reasoning via Self-Evolving Skill Memory
Haoran Sun, Wenjie Li, Yujie Zhang et al. (+8 more)
Medical
agent systems are increasingly expected to support interactive clinical decision making rather than only static question answering. In such settings, effective
agents must reuse prior experience across evolving cases, yet existing
memory mechanisms often retain raw historical traces that are redundant, noisy, and difficult to govern. More importantly, they rarely distinguish which
memories are truly useful for future
reasoning. This limits their ability to accumulate compact and reliable experience for long-horizon clinical
reasoning. To close this gap, we propose SkeMex, a post-deployment self-
evolution framework that improves medical
agents through a skill-based
memory without updating model weights. SkeMex distills informative interaction trajectories into structured skills that encode reusable procedural knowledge, and organizes them into a multi-branch repository spanning general, task-specific, and action-level experience. To determine which
memories should be reused and retained, SkeMex estimates context-dependent utility from environment feedback and uses it to guide value-aware
retrieval and repository governance. A closed-loop “Read–Write–Assess–Govern" lifecycle further supports continual
evolution by writing new skills, updating utilities, promoting useful
memories, and removing harmful entries. Experiments across diverse clinical tasks show that SkeMex consistently outperforms representative
memory-based
agents in both offline and online settings. It also generalizes across model backbones and supports transferable skill
memory. All data and code will be released publicly.
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All authors Haoran Sun, Wenjie Li, Yujie Zhang, Zekai Lin, Fanrui Zhang, Kaitao Chen, Xingqi He, Yichen Li, Mianxin Liu, Lei Liu, Yankai Jiang
Computation and Language
In-Context Learning for the Imputation of Public Opinion Data with Large Language Models
Tobias Holtdirk, Georg Ahnert, Joseph W Sakshaug et al. (+1 more)
Large
language models have been widely evaluated as simulators of individual survey responses. In practice, however, fully unobserved responses are rare; the dominant problem is partial non-response. Imputation aims to restore the overall structure of a survey
dataset by filling in these missing values. It has its own well-defined evaluation criteria and differs fundamentally from prediction. We propose to impute missing survey data through in-context learning (ICL). We systematically evaluate ICL design choices across different missingness mechanisms (MCAR, MAR, MNAR) on 150 opinion variables spanning 15 waves of the American Trends Panel. Compared to well-established statistical methods for data imputation like MICE PMM, our ICL approach consistently reduces absolute error across all missingness mechanisms, with the largest gains under non-random missingness (MNAR). Notably, the best-performing specification (gpt-oss-120b with 100 in-context examples) achieves near-nominal aggregate coverage (approaching the 95% level) with confidence intervals two to five times narrower than MICE PMM. We publish a Python package with an sklearn-like API to enable easy deployment of our method using local and proprietary LLMs.
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All authors Tobias Holtdirk, Georg Ahnert, Joseph W Sakshaug, Anna-Carolina Haensch
Computation and Language · Cross-listed from cs.LG
PBSD: Privileged Bayesian Self-Distillation for Long-Horizon Credit Assignment
Yang Tian, Rui Wang, Xumeng Wen et al. (+5 more)
Long-horizon agentic tasks pose a fundamental credit assignment challenge for outcome-base reinforcement learning: trajectory-level rewards verify final correctness but provide limited guidance on which intermediate
reasoning steps or tool interactions contribute to the outcome. The difficulty is especially pronounced in multi-turn search
agents, where successful trajectories may contain misleading actions and failed trajectories may contain valuable evidence-gathering steps. We propose PBSD (Privileged
Bayesian Self-
Distillation), a Bayes-calibrated self-
distillation method for fine-grained credit assignment under sparse final rewards. PBSD measures trajectory quality through the posterior-to-prior probability ratio of the verified answer and applies Bayes' rule to convert this hard-to-estimate answer-side ratio into a tractable likelihood ratio between a standard student model and a privileged answer-conditioned teacher model. Autoregressive decomposition of this
Bayesian evidence score yields turn-level signals that identify whether each intermediate turn supports or undermines the verified outcome. Consequently, PBSD provides a principled and elegant reweighting scheme that transforms sparse outcome supervision into Bayes-calibrated turn-level credit signals, while remaining fully compatible with standard policy optimization. Experiments demonstrate that PBSD consistently enhances performance across both in-domain and out-of-domain settings, and effectively transfers knowledge from short-context training to long-context inference, suggesting that its fine-grained credit assignment mechanism facilitates more effective policy learning and yields improved generalization.
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All authors Yang Tian, Rui Wang, Xumeng Wen, Junjie Li, Shizhao Sun, Lei Song, Jiang Bian, Bo Zhao
Computation and Language
Multi-Hop Knowledge Composition is Bound by Pretraining Exposure
Yannis Karmim, Luis Marti, Djamé Seddah et al. (+1 more)
Large
Language Models fail at implicit multi-hop
reasoning: a model answers "When was $X$ born?" and "Who is $Y$'s closest friend?" correctly but fails on "When was $Y$'s closest friend born?" in a single forward pass, even when both facts are perfectly memorized and individually retrievable. We study this failure in a controlled natural
language setting with a strict separation between individuals exposed to compositional contexts during pretraining and those that never appear in any such context. We confirm that compositional failure persists even at 97% 1-hop accuracy, establishing the gap as a pretraining failure rather than a knowledge absence. We propose and test nine data-centric augmentation formats and find that compositional pretraining transfers to unseen questions for exposed individuals, but never to individuals absent from compositional pretraining, suggesting that exposure to compositional contexts during pretraining is a necessary condition for implicit multi-hop
reasoning. Code is available at https://github.com/ykrmm/composition-bound .
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All authors Yannis Karmim, Luis Marti, Djamé Seddah, Valentin Barrière
Computation and Language
How Far Can Prompting Go for Minimal-Edit Ukrainian Grammatical Error Correction?
Kateryna Karpo and Artem Chernodub
Fine-tuned Large
Language Models (LLMs) dominate in Ukrainian grammatical error correction (GEC), while API-accessed LLMs remain nearly untested on minimal-edit
benchmarks. We evaluate 11 commercial LLMs from four providers and one open-source Ukrainian model on the UNLP 2023 GEC-only
benchmark, comparing zero-shot, few-shot, minimal-edits, and LLM-assisted
prompt optimization strategies. Our best configuration (Gemini 3.1-Pro) reaches F0.5=69.22, closing over 90% of the gap to fine-tuned SOTA (F0.5=73.14). For zero-shot
prompts, only Claude models benefit from Ukrainian instructions. However, the best overall results for all models use Ukrainian minimal-edits
prompts, whose
language-specific rules require Ukrainian to express precisely. LLM-assisted
prompt optimization on top of minimal-edits + few-shot achieves the highest score. Detailed minimal-edits instructions yield the largest gains for punctuation and case errors but cause the model to abandon several low-frequency categories. Delving into error analysis, we identify five recurring overcorrection patterns tied to Ukrainian-specific linguistic phenomena. Code,
prompts, and outputs are publicly available.
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Computation and Language
SG-OPD: Sign-Gated On-Policy Distillation via Sign-Consistency Gating and Phased Teacher Sampling
Haoran Xu, Hongyu Wang, Yifei Gao et al. (+3 more)
On-policy
distillation (OPD) trains a student on its own trajectories with dense per-
token supervision from a stronger teacher, and often outperforms off-policy
distillation and standard reinforcement learning. However, we find that its effectiveness implicitly relies on two assumptions that frequently break in practice: trajectory-level
alignment between the student and the teacher, and uniform
token-level reliability of the teacher's preferences. We therefore propose Sign-Gated On-Policy
Distillation (SG-OPD), which uses a binary verifier as a trust signal for the teacher at two complementary granularities: phased teacher sampling mixes in verifier-endorsed teacher rollouts at cold-start, and a sign-consistency gate extrapolates the
distillation update on
tokens where the teacher agrees with the verifier-correct direction and interpolates it where it disagrees. Experiments on competition-level mathematical
reasoning benchmarks show that SG-OPD consistently outperforms standard OPD, with average gains of 1.98 and 7.50 at the per-sample and per-question levels, respectively.
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All authors Haoran Xu, Hongyu Wang, Yifei Gao, Jiaze Li, Xiaofeng Zhang, Xiaosong Yuan
Computation and Language
NüshuVoice: Reviving the Voice of Endangered Nüshu with Pitch-Aware Text-to-Speech
Hongkun Yang, Xinhui Yi, Xiyan Zhao et al. (+13 more)
Nüshu is an endangered phonetic script historically used by women in Jiangyong County, southern Hunan, China. While existing computational studies of Nüshu mainly focus on textual digitization and visual recognition, the acoustic reconstruction of its authentic pronunciation remains largely unexplored. Building a Nüshu text-to-
speech (TTS) system is particularly challenging because available recordings are extremely limited and mostly consist of isolated syllable-level pronunciations rather than natural sentence-level utterances. In this work, we introduce NüshuVoice, the first TTS
benchmark for Nüshu. We construct a sentence-level Nüshu text-to-audio
dataset that aligns standardized Unicode Nüshu text, phonetic transcriptions, standard Chinese translations, and archival recordings. To synthesize
speech under this extreme low-resource setting, we propose Nüshu-PitchVITS, an F0-conditioned VITS framework that leverages Nüshu's five-level pitch notation as an explicit prosodic inductive bias. Experimental results show that Nüshu-PitchVITS outperforms strong TTS baselines in spectral fidelity, pitch reconstruction, and human-rated intelligibility. We publicly release the
dataset and code at: https://anonymous.4open.science/r/Nvshu-TTS-2EB6.
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All authors Hongkun Yang, Xinhui Yi, Xiyan Zhao, Yibo Meng, Lionel Z. Wang, Lixu Wang, Yaqi Zhang, Ruiqi Chen, Xuanyue Zhao, Lanxin Zhang, Yu Zeng, Weijia Chu, Yiming Ma, Chenyu Liu, Jianghao Lin, Xin Xu
Computation and Language
One Model, Multiple Goals: Adaptive Multi-Objective Learning for E-commerce Dialogue Systems
Mingzhe Li, Jing Xiang, Enguo Zhou et al. (+5 more)
Dialogue systems in e-commerce scenarios often need to satisfy multiple objectives: accurately
reasoning over user profiles (e.g., eligibility, credit limit) to ensure correct decision-making and user state interpretation, while also generating natural and faithful responses. These goals are complementary but not identical. In this work, we propose MORE, an adaptive Multi-Objective REinforcement learning framework that jointly optimizes
reasoning accuracy and linguistic naturalness. Our preliminary experiments show that directly mixing rewards with diverging optimization dynamics can cause oscillations and unstable learning. Thus, instead of optimizing a single mixed reward, we treat
reasoning functions as constraints that guide policy optimization. At inference time, the system directly generates responses without explicit
reasoning steps, while still benefiting from
reasoning-enhanced scaffold and avoiding additional inference overhead. To better balance linguistic objectives during response generation, we introduce an adaptive multi-reward mechanism that aggregates signals such as fluency and naturalness and dynamically reweighs them via gradient feedback. We evaluate MORE on two real-world dialogue systems at ByteDance and the MultiWOZ 2.2
benchmark, where it consistently outperforms strong baselines. In 14-day online experiments on ByteDance production traffic, MORE improves overall and reached conversion by 16.53% and 30.09%, while increasing user satisfaction and reducing handoff rates. Notably, in a human-machine comparison, MORE recovers about 60% of the incremental conversion lift achieved by human
agents.
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All authors Mingzhe Li, Jing Xiang, Enguo Zhou, Lang Gao, Tai Li, Qishen Zhang, Xiangliang Zhang, Xiuying Chen
Computation and Language
TruthSplit: Operationalizing Conditional Validity in Arguments Through Multi-Perspective Reasoning
Benjamin Stieger, Maximilian Terberger, Thomas Huber et al. (+1 more)
We present TruthSplit, an interactive system for multi-perspective argument analysis. Existing argumentation tools typically analyze properties of the argument itself, such as structure, quality, stance, or persuasiveness, while leaving perspective-specific background knowledge implicit. TruthSplit addresses this gap by supporting an exploratory analysis of how the same claim can lead to different conclusions when interpreted through worldview-specific values, assumptions, and conceptual definitions. We refer to this perspective-dependent analysis as conditional validity. Given an input argumentative text, TruthSplit extracts claims and premises, applies a three-layer natural
language inference (NLI) approach to assess both logical and worldview-specific normative consistency, and conditions large
language model (LLM)
reasoning on structured worldview profiles that encode core values and decision principles. The system then generates perspective-specific interpretations, identifies value conflicts and assumption gaps, and visualizes divergence through interactive analytical interfaces.
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All authors Benjamin Stieger, Maximilian Terberger, Thomas Huber, Christina Niklaus
Computation and Language · Cross-listed from cs.LG
The Injection Paradox: Brand-Level Suppression in Safety-Trained LLM Recommendations via RAG Context Injection
Hyunseok Paeng
We present a reproducible failure mode of safety training in RAG-based LLM recommendation, the Injection Paradox, in which
prompt injections embedded in retrieved documents backfire against the attacker, suppressing the target brand below the injection-free baseline. In safety-trained Claude models, documents containing
prompt injections suffer a sharp drop in recommendation rate, and this suppression propagates beyond the injected document to unmodified documents of the same brand. In Claude Opus 4.6, the target brand drops from a 54% baseline to zero top-2 recommendations across all 50 trials, even though only 1 of 4 brand documents in the corpus contains an injection. The directional pattern is reproduced in counterfactual experiments and across three brands. A contrasting result across the GPT models tested, where the same injection instead increases recommendations, suggests model-family differences in how injection-like context affects recommendation behavior. These findings raise the technical possibility of a reverse-attack scenario in which an adversary embeds injections in a competitor's documents to suppress the competitor's brand via safety-sensitive model behavior. Code,
prompts,
privacy-preserving per-trial outcome records, and aggregate results are released.
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Computation and Language
Symbolic and Abstractive Reasoning with Complex Visual Queries
Yichi Zhang, Jingdian Lu, Zhuo Chen et al. (+4 more)
Understanding and
reasoning over abstract visual content remains a challenge for current multi-modal large
language models (MLLMs). In this paper, we explore a novel abstract data type termed complex visual query (CVQ), designed to probe symbolic and abstractive
reasoning, which is a critical yet underexplored dimension of human-like neuro-symbolic
reasoning for MLLMs. We present a comprehensive investigation from three perspectives: \textbf{Data $\times$ Paradigm $\times$ Exploration}. Specifically, we propose a scalable pipeline for synthesizing CVQs grounded in large-scale multi-modal knowledge graphs, generating a diverse
dataset encompassing 14 distinct query types via systematic combinations of first-order logic operators. We further introduce a two-stage training framework that progressively equips MLLMs with robust visual
reasoning capabilities. We conduct extensive experiments to rigorously evaluate MLLMs across multiple dimensions, including
reasoning performance on CVQs, as well as cross-task and cross-scenario generalization. We believe our work opens new perspectives and avenues for advancing the
reasoning frontiers of MLLMs.
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All authors Yichi Zhang, Jingdian Lu, Zhuo Chen, Lingbing Guo, Jun Xu, Wen Zhang, Huajun Chen
Computation and Language
Culturally-Adapted Red-Teaming Across East and Southeast Asian Contexts: A Methodological and Comparative Analysis
Hyeji Choi, Yongtaek Lim and Minwoo Kim
Multilingual safety evaluation of large
language models (LLMs) has predominantly relied on direct translation (DT) of English
benchmarks into target
languages - an approach that converts surface-level linguistic form while failing to reflect the cultural context embedded in threat scenarios, social norms, and legal frameworks. We construct paired DT and culturally-adapted (CA)
datasets via 1:1 seed matching for four
languages - Korean (KO), Japanese (JA), Thai (TH), and Khmer (KM) - and compare Attack Success Rate (ASR) and Cultural Realism scores across four open-source LLM. CA
prompts yield Delta-ASR > 0 across all 16
language x model combinations (mean +9.3 pp), and DT-based evaluation underestimates risk in 44 of 48 category x
language combinations.
Language-level analysis reveals that the distribution of threat forms is heterogeneous across
languages. Cultural Realism analysis further shows that DT Cultural Depth (C3) scores remain consistently below 1.0 out of 3.0 across all four
languages (mean 0.17), whereas CA scores reach up to 2.51, indicating that direct translation produces inputs systematically divergent from those encountered in real-world multicultural settings. These findings demonstrate that adapting
benchmarks to
language-specific cultural contexts - rather than relying on linguistic translation alone - is necessary for valid
multilingual LLM safety evaluation.
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Computation and Language
Unified Energy for Invariant and Independent Decoding in Diffusion Language Models
Yuchen Yan, Minkai Xu, Zaiquan Yang et al. (+1 more)
Diffusion Language Models (DLMs) enable parallel text generation by iteratively denoising a full sequence, offering attractive flexibility compared to auto-regressive (AR) decoding. However, existing methods fail to fully capture
token relationships, leading to a performance gap relative to AR baselines, especially as the degree of parallelism increases. In this paper, we give a systematic analysis of the gap, identifying three key factors: (i) model capacity, (ii) dependency, and (iii) invariance. To address these issues, we first propose an invariant energy (Inv-E) together with an effective sampling-based
estimator to handle the invariance issue. By further combining with the independent energy (Ind-E), we obtain a unified energy (Uni-E), that accounts for all these factors. Uni-E enjoys a unique advantage: it can be computed exactly without sampling-based partition estimation. Besides, Uni-E is model agnostic and can therefore be scaled to models of arbitrary size. We further prove that Uni-E can correct the distribution shift caused by dependency and invariance. Extensive experiments across
Diffusion Language Models (DLMs) and
Diffusion Large
Language Models (DLLMs) demonstrate the effectiveness of the proposed Uni-E.
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All authors Yuchen Yan, Minkai Xu, Zaiquan Yang, Yatao Bian
Computation and Language
SEF-CLGC at SemEval-2026 Task 11: Logical Notation Impact on Language Model Performance
Hanna Abi Akl, Fabien Gandon, Catherine Faron et al. (+1 more)
This paper revisits our pipeline called Syllogistic Evaluation Framework-Common Logic Grammar Construction (SEF-CLGC). We combine formal logical notations with Small
Language Models (SLMs) to evaluate
reasoning performance on the SemEval-2026 Task 11 Subtask 1: Disentangling Content and Formal
Reasoning in Large
Language Models. Our experiments show that by relying solely on SLMs, trained on a combination of natural and symbolic
languages, our best model achieves a content score of 27.80% on the task while significantly lowering the content bias in
reasoning.
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All authors Hanna Abi Akl, Fabien Gandon, Catherine Faron, Pierre Monnin
Computation and Language
Explicit Representation Alignment for Multimodal Sentiment Analysis
Baode Wang, Ziming Wang, Huacan Wang et al. (+2 more)
Multimodal affective analysis aims to understand human sentiment and
emotion by jointly modeling heterogeneous modalities such as text and images. However,
multimodal models often fail to consistently outperform strong text-only baselines, with performance varying significantly across fusion strategies. In this work, we identify representation misalignment between independently pretrained modality encoders as a key bottleneck for effective
multimodal learning, and show through controlled experiments that
alignment prior to fusion is often more important than fusion complexity. To address this issue, we propose a unified
multimodal affective analysis framework that leverages
vision-
language models (VLMs) to convert visual content into structured textual descriptions, projecting heterogeneous modalities into a shared linguistic space and enabling interpretable text-centric
reasoning. To further improve robustness, we introduce a hybrid learning strategy that combines semantic
token selection with a batch-level uniformity regularization objective, encouraging a more dispersed and stable global feature space while mitigating noise introduced by VLM-generated descriptions. Experiments on multiple
multimodal sentiment and
emotion benchmarks show that our method consistently outperforms strong unimodal and
multimodal baselines, achieving state-of-the-art performance. Our analysis further highlights the critical role of representation
alignment in
multimodal affective learning.
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All authors Baode Wang, Ziming Wang, Huacan Wang, Ronghao Chen, Biao Wu
Computation and Language · Cross-listed from cs.LG
AgentWorld: A Data Factory for Training LLM Agents from Multi-Turn Interactions
Daoyu Wang, Mingyue Cheng, Qingchuan Li et al. (+4 more)
Training LLMs to act as capable
agents requires learning from multi-turn interactions with environments. However, multi-turn interaction trajectories generated by heterogeneous
agent runtimes are difficult to transform into structured, high-quality training data that training engines can readily consume. In this paper, we propose AgentWorld, a data factory that bridges heterogeneous
agent runtimes and training engines through a Gateway Server and a Data Pool, reframing LLM
agent training around a unified data lifecycle from interaction collection to training consumption. The Gateway Server captures multi-turn interactions through an LLM API proxy, while the Data Pool organizes them into standardized step records for curation and training. An interactive dashboard supports trajectory monitoring, step inspection, and data review. In our demonstration, users integrate ready-to-use white-box and black-box
agents, trace and curate their interaction data across the pipeline, and extend the factory to new
agents and
datasets through lightweight configuration. Quantitative experiments across multiple
datasets and RL methods demonstrate training support for different
agent runtimes. AgentWorld provides a practical foundation for transforming heterogeneous multi-turn experience into training-ready data for LLM
agents. Our code is available at https://github.com/AgentR1/Claw-R1 and the demonstration
video can be found at link https://youtu.be/Pw47dAOw6B0.
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All authors Daoyu Wang, Mingyue Cheng, Qingchuan Li, Shuo Yu, Jie Ouyang, Qi Liu, Enhong Chen
Computation and Language · Cross-listed from cs.RO
From USD Scenes to Knowledge Graphs: Zero-Shot Ontology Grounding with LLMs
Jiangtao Shuai, Zongxiong Chen, Manfred Hauswirth et al. (+1 more)
Constructing knowledge graphs from 3D simulation scenes is essential for
robot task
reasoning, but the key bottleneck, grounding scene objects to formal ontology classes, still relies on manually curated dictionaries that are brittle and do not generalize across assets. We investigate whether large
language models (LLMs) can automate this grounding step for Universal Scene Description (USD) scenes as a zero-shot, training-free alternative. On a kitchen scene (125 objects) with SOMA-HOME Ontology, LLMs achieve 90-96% exact-match accuracy with descriptive names and 49-89% with abbreviated names, substantially outperforming dictionary and
embedding baselines. Under fully opaque names, context-augmented prompting recovers up to 48%. Feature ablation reveals that LLMs primarily exploit semantic cues in the scene graph (sibling names and parent paths); anonymizing these cues reduces accuracy to 0-6%, while geometry alone yields only 4-17%.
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All authors Jiangtao Shuai, Zongxiong Chen, Manfred Hauswirth, Sonja Schimmler
Computation and Language · Cross-listed from cs.AI
Late-Layer Fusion is Enough: Dual-Path Vision Token Routing for Multimodal Large Language Models under Visual Saturation
Siyuan Liu and Jinyang Wu
Multimodal large
language models (MLLMs) commonly inherit the deep, symmetric
Transformer backbone designed for unimodal text modeling, and apply the same computation uniformly to image and
language tokens. This design overlooks a key modality asymmetry: image and text
tokens differ substantially in information density, redundancy, and required
reasoning depth. Through a layer-wise analysis of LLaVA-1.5, we observe that
vision tokens tend to saturate in the middle layers. Specifically, text-to-image
attention decreases from 0.68 at layer 0 to 0.07 by layer 4, and stabilizes near 0.04 after layer 18, whereas text
tokens continue to benefit from deep semantic processing. These findings suggest a mismatch between architectural
symmetry and depth-asynchronous modality
evolution, resulting in redundant visual computation and possible drift in perceptual representations during deep task-specific adaptation. Motivated by this, we propose Dual-Path
Vision Token Routing (DPVR), a modality-asymmetric routing framework for efficient MLLMs. Its core instantiation, DPVR-LF (Late-Layer Fusion), routes
vision tokens at the saturation point into a one-layer trainable side branch, runs a thirteen-layer text-only forward that skips image positions in the deep stack, and re-fuses the visual and textual streams only at the final layer. With approximately 3% trainable parameters, DPVR-LF preserves competitive
multimodal performance on standard
benchmarks while reducing visual computation in the deep
Transformer stack. The results challenge the conventional assumption that
vision tokens must traverse all deep
language-model layers, and indicate that a single late fusion layer can be sufficient for maintaining strong perceptual competence in LLaVA-style MLLMs.
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Computation and Language
MAAM: Anchor-Preserving Compression and Contextual Calibration for Chinese Discriminatory Language Detection
Yuxin Fu and Shijing Si
Chinese discriminatory-
language detection is challenging because harmful intent is often implicit and context-dependent. We propose MAAM (Myopia–Astigmatism Anchor Mechanism), a lightweight, model-agnostic framework inspired by functional visual blur: rather than preserving every
token equally, MAAM retains discrimination-relevant semantic anchors and calibrates them with C–I–S contextual priors (Contextual Tone, Group Identity, and Stance Polarity). We also introduce ChLGBT, to our knowledge the first Chinese LGBT-focused discriminatory-
language dataset, with 8,120 manually annotated samples and three ordinal labels: explicit bias, implicit bias, and emotional intensity. Across strong encoder baselines, MAAM improves all three prediction dimensions, with consistent gains in accuracy, F1, Brier score, and expected calibration error. Compared with frontier LLM baselines under zero-shot and few-shot prompting protocols, MAAM remains competitive while offering stronger compactness and stability. These results suggest that interpretable anchor preservation and contextual calibration provide a practical alternative to heavier model scaling for Chinese discriminatory-
language assessment.
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Computation and Language · Cross-listed from cs.LG
Beyond FLOPs: Benchmarking Real Inference Acceleration of LLM Pruning under a GEMM-Centric Taxonomy
Haozhe Hu, Hao Wu, Anhao Zhao et al. (+4 more)
Pruning has emerged as a dominant paradigm for accelerating large
language model (LLM) inference, spanning a broad spectrum of methods that remove computation across
tokens, layers, heads, dimensions, and
attention patterns. Despite sharing the same objective, these
pruning approaches induce fundamentally different execution behaviors, causing realized speedups to depend heavily on hardware and kernel implementations. Consequently, the practical acceleration benefits of different
pruning families remain poorly understood. In this work, we introduce a GEMM-centric taxonomy that reorganizes existing
pruning methods according to the logical M, N, and K dimensions of general
matrix multiplication (GEMM). Leveraging this abstraction, we build a unified benchmarking framework that enables implementation-consistent comparison across the
pruning design space and systematically characterizes the acceleration–quality Pareto frontier. Our results on Llama3.1-8B show that static depth
pruning remains the strongest Pareto-optimal baseline and stays closest to its theoretical acceleration upper bound in
memory-bounded scenarios. During prefill, the frontier transitions from static depth at low quality loss (0%–4%), to dynamic depth at moderate loss (5%–16%), and finally to static width
pruning at higher loss levels (17%–26%). These findings establish the first unified view of the practical limits of
pruning-based LLM acceleration and provide guidance for future
pruning research. Code is available at https://github.com/EIT-NLP/LLM-
Pruning/tree/main/PruningInferSim
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All authors Haozhe Hu, Hao Wu, Anhao Zhao, Longwei Ding, Peiran Yin, Yunpu Ma, Xiaoyu Shen
Computation and Language · Cross-listed from cs.LG
A Unifying Lens on Reward Uncertainty in RLHF
Ely Hahami, Yoel Zimmermann, Ray Zhou et al. (+1 more)
Reinforcement learning from human feedback (RLHF) is bottlenecked by reward hacking, where the policy exploits errors in a proxy reward model (RM) and produces high RM scores without genuine quality gains. A natural mitigation is pessimism: lowering rewards in regions where the RM is uncertain. However, standard scalar RMs provide no principled notion of uncertainty. We argue that the right object is a distributional reward model $p(r\mid x,y)$. Under either a
Bayesian inference or a KL-distributionally robust optimization (KL-DRO) lens, the KL-regularized RLHF objective admits a closed-form effective reward $\tilde r(x,y) = \pm\beta\log\mathbb{E}_p[e^{\pm r/\beta}]$. The pessimistic branch unifies the prior heuristics for RM ensemble aggregation: mean aggregation, worst-case optimization (WCO), and uncertainty-weighted optimization (UWO) all emerge as limits or truncations of this single expression. This also clarifies the implicit assumptions of each existing rule.
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All authors Ely Hahami, Yoel Zimmermann, Ray Zhou, Jack Benarroch Jedlicki
Computation and Language
Emergent Misalignment Can Be Induced by Sycophancy and Reversed via Alignment Gating
Sicheng Wang, Xiangyang Zhu, Han Wang et al. (+6 more)
Prior work has shown that fine-tuning large
language models on malicious or incorrect outputs in narrow domains can induce broad misalignment and harmful behavior, a phenomenon known as emergent misalignment. However, efficient methods for reversing such misalignment remain limited. In this work, we make two contributions. First, we identify sycophancy fine-tuning, i.e., training models to passively agree with users' incorrect opinions, as a previously underexplored driver of emergent misalignment, and show that it induces broad and severe misaligned behavior. Second, we propose
Alignment Gating, an efficient method for reversing emergent misalignment that inserts learnable and controllable gates into the model during fine-tuning. Through fine-tuning, these gates learn to identify the internal representations responsible for unsafe responses. Thus, amplifying or suppressing these representations then exacerbates or mitigates EM, respectively. We further find that
alignment gating module exhibits strong generalization: gating weights obtained from narrow-domain fine-tuning substantially suppress broad-domain misaligned behavior while preserving the model's general capabilities.
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All authors Sicheng Wang, Xiangyang Zhu, Han Wang, Zongrui Wang, Yuan Tian, Kaiwei Zhang, Kaiyuan Ji, Qi Jia, Guangtao Zhai