Computation and Language
SciDiagramEdit: Learning to Edit Scientific Diagrams from Paper Revisions
Yasheng Sun, Zezi Zeng, Yifan Yang et al. (+4 more)
Editing the figures in a research paper is a routine and time-consuming part of everyday research practice: authors relabel components, rearrange panels, and restyle visuals as they revise their manuscripts. Automating this editing workflow under a natural-
language instruction, however, is challenging, because a scientific figure is a dense infographic in which heterogeneous visual elements such as schematics, plots, photos, captions, and arrows are composed under a tight visual grammar to advance a specific argument. To address this, we present SciDiagramEdit, a
benchmark and skill-
evolution framework that learns from natural paper revisions and operates on the figure's editable vector source, where users can inspect and co-edit individual primitives alongside the
agent. Our
benchmark mines before/after figure pairs from arXiv version histories, each grounded in the authors' own revision intent. To accommodate the diversity of editing instructions, we adopt agentic learning via skill
evolution: an agentic proposer continually refines the
agent's skill specification from execution traces over multiple epochs. The resulting skill progressively lifts edit accuracy on a held-out validation set, providing evidence that natural paper revisions are an effective training signal for instruction-driven figure editing.
Read the full abstract ▾
All authors Yasheng Sun, Zezi Zeng, Yifan Yang, Chong Luo, Wenyi Wang, Ziwei Liu, Jürgen Schmidhuber
Computation and Language · Cross-listed from cs.AI
Pretraining Data Can Be Poisoned through Computational Propaganda
Victoria Graf, Hannaneh Hajishirzi, Noah A. Smith et al. (+2 more)
Poisoning pretraining data can introduce harmful behaviors to LMs that are difficult to detect and mitigate. Prior work on poisoning pretraining data has largely exploited established data sources such as Wikipedia, which do not represent the large scale and heterogeneity typical of pretraining corpora, and has ignored the interaction between poisoned data and data curation pipelines. We demonstrate that poisoning attacks on pretraining data are feasible beyond this limited setting through an existing web-scale content injection mechanism: public discussion interfaces. Additionally, to measure whether malicious content is included after web crawling and data curation, we introduce HalfLife, a novel analysis for estimating
adversarial content inclusion in web-crawl based LM training data. We use HalfLife to explore the feasibility of poisoning pretraining corpora at web scale through open discussion interfaces. Our analysis demonstrates the importance of estimating whether poison injections are included in pretraining data, and establishes third-party webpage content as a possible vector for attacking
language model pretraining.
Read the full abstract ▾
All authors Victoria Graf, Hannaneh Hajishirzi, Noah A. Smith, David Kohlbrenner, Kyle Lo
Computation and Language · Cross-listed from cs.IR
Bridge Evidence: Static Retrieval Utility Does Not Predict Causal Utility in Multi-Step Agentic Search
Debayan Mukhopadhyay, Utshab Kumar Ghosh and Shubham Chatterjee
Retrieval systems are trained and evaluated on a static idea of usefulness: hand a document and a question to a reader model, see whether the answer improves, and score the document accordingly. The idea holds up when a document is read on its own. It breaks when a
language model works as a search
agent, issuing several queries and
reasoning across turns, because a document can matter for what it lets the
agent do next rather than for what it says about the current question. We measure that gap rather than argue it. Using a ReAct style
agent over HotpotQA, we replay 1000 development questions and, for every document the
agent read, delete it and re-run the rest of the trajectory from that point. Comparing the original run against its counterfactual gives a Counterfactual Trajectory Utility (CTU) score from three deltas: final answer quality, next query
retrieval quality, and turn count. Crossing CTU against Static RAG Utility (SRU) over 23,322 document observations, the two are close to statistically independent (Spearman rho = -0.026). Roughly a third of the documents the
agent reads are causally load bearing while looking useless to a static reader; we call these bridge documents. The pattern survives when the reader based axis is swapped for a BM25 and cross encoder proxy, giving a bridge
cell of 27.2% on an evenly spread axis. A second experiment pins down the mechanism. Using the Observable Entity Relevance (OER) measure from prior work, entities that discriminate relevant from non-relevant candidates appear in the
agent's next query 4.02 times more often than entities found only in non-relevant documents (6.1% vs 1.5%, n = 227,139). A bridge document earns its keep by handing the
agent a discriminative entity that redirects the search. Static relevance and causal usefulness are different quantities in agentic
retrieval, and optimizing the first does not deliver the second.
Read the full abstract ▾
Computation and Language
Beyond the Leaderboard: Design Lessons for Trustworthy Multimodal VQA
Sushant Gautam, Vajira Thambawita, Michael A. Riegler et al. (+2 more)
Healthcare
multimodal AI must combine visual and textual evidence while remaining reliable and interpretable. Using MediaEval Medico 2025 as a retrospective GI endoscopy case study, we analyze design choices across nine documented systems for question answering and explanation quality. Parameter-efficient adaptation of pretrained backbones provides strong challenge performance, but answer-level gains do not consistently translate into faithful and complete clinical
reasoning. Methods enforcing structured
reasoning and explicit grounding show more reliable behavior across heterogeneous question types, although the evidence is correlational rather than ablation-based. These results motivate evaluation beyond lexical overlap, standardized evidence-linked explanations, leakage-aware data governance, and lightweight robustness and calibration checks. The findings support trustworthy
multimodal healthcare AI based on data fusion, explainability, and resilient evaluation.
Read the full abstract ▾
All authors Sushant Gautam, Vajira Thambawita, Michael A. Riegler, Pål Halvorsen, Steven A. Hicks
Computation and Language
TikStance: A Multimodal and Hierarchical Dataset for Multi-target Stance Analysis in TikTok Political Conversations
Yazhi Zhang, Fuqiang Niu and Bowen Zhang
Political discourse has increasingly moved to short-
video platforms, yet computational analysis of such content remains constrained by the scarcity of
datasets that jointly preserve audiovisual information and hierarchical conversations. Here we present TikStance, a
multimodal and context-aware
dataset comprising 161
videos and 13,876 comments from TikTok, designed for stance detection in political discussions. The
dataset covers three major political figures in the 2024 U.S. election cycle–Donald Trump, Joe Biden, and Kamala Harris–with content collected between September 2023 and January 2025. Each discussion unit links a host
video and its metadata to a parent-linked comment tree, enabling stance analysis within both audiovisual and conversational context. Each item was independently labeled by three annotators using a three-class scheme (Favor, Against, None) for
video-to-target and comment-to-target stance; items with disagreement were re-annotated, and the final Krippendorff's \(\alpha\) reached 0.743, 0.723, and 0.722 for the Trump, Biden, and Harris subsets, respectively. Descriptive analysis further reveals target-dependent differences in stance distributions and conversational depth, with nested replies accounting for 23.3% of all comments. By combining multi-target coverage, hierarchical conversations, and reliable multi-level human annotations, TikStance supports research in
multimodal stance detection, political communication, computational social science, and context-aware natural
language processing.
Read the full abstract ▾
Computation and Language
Language Identification via Compositional Data Analysis: A Linear-Time Classifier Based on Log-Ratio Geometry
Paul-Andrei Pogăcean and Sanda-Maria Avram
Language identification is commonly addressed using either neural architectures or statistical n-gram models. Neural approaches typically require substantial computational resources, whereas classical frequency-based methods offer efficient linear-time performance, but rely on distance metrics that are not always appropriate for compositional data. This work models character and bigram frequency distributions as compositional vectors constrained to the simplex and mapped via the centered log-ratio (CLR) transformation bijectively onto the $(D-1)$-dimensional zero-sum subspace of $\mathbb{R}^D$, where Euclidean distances correspond to Aitchison distances. A pipeline is proposed, combining CLR-transformed unigram and bigram features with Laplace smoothing to address sparsity. The method is evaluated on six
languages. Experimental results show that the proposed approach achieves robust accuracy across different text lengths, with strong performance for longer sequences. These findings indicate that compositional representations provide a deterministic and computationally efficient alternative for
language identification, particularly in settings where interpretability and low resource consumption are essential.
Read the full abstract ▾
Computation and Language
In-Place Tokenizer Expansion for Pre-trained LLMs
Jimmy T.H. Smith, Tarek Dakhran, Alberto Cabrera et al. (+7 more)
A tokenizer fixed at the start of pre-training allocates vocabulary in proportion to the pre-training corpus, reflecting the deployment priorities at that time. When those priorities shift,
languages added later are split into many more
tokens per word, which can raise latency, compute, and energy consumption for users of those
languages. Cloud models can afford a broad vocabulary because the
embedding and LM-head
matrices are a small fraction of their parameters. On a compact model those
matrices are a material share of per-
token decode bandwidth, so on-device models ship small vocabularies and accept fragmentation outside a fixed
language set. We present tokenizer expansion, an in-place recipe for upgrading a pre-trained model's tokenizer when the model producer controls its design. We continue the existing tokenizer's BPE merges on a
multilingual corpus, so most source
tokens carry over unchanged as single
tokens and every new
token has an exact decomposition into source
tokens. We copy the carried-over
embedding rows unchanged and initialize new rows as the mean of their source sub-
token embeddings. A two-stage adaptation,
embedding-only training then full-model continued pre-training, recovers source-checkpoint quality. We apply the recipe to a continued pre-trained checkpoint of LFM2-8B-A1B, an 8B-parameter Mixture-of-Experts model, to help produce LFM2.5-8B-A1B with a 128K tokenizer. The expanded tokenizer encodes Hindi and Vietnamese in roughly $2.4\times$ and $2.6\times$ fewer
tokens than the source (up to $4.0\times$ on Thai). Combining these reductions with the measured per-
token cost of the larger vocabulary, we estimate a $2.2$-$3.7\times$ per-character decode speedup for these
languages across our reference devices. We release the model weights and the expanded tokenizer, and report the negative findings that shaped the recipe.
Read the full abstract ▾
All authors Jimmy T.H. Smith, Tarek Dakhran, Alberto Cabrera, Simon S. Lee, Paul Pak, Aditya Tadimeti, Tim Seyde, Maxime Labonne, Alexander Amini, Mathias Lechner
Computation and Language
Expanding the Lexicon of Ge'ez Based African Languages: A Comparative Study of Amharic and Tigrinya
Hailay Kidu Teklehaymanot, Debela Desalegn Yadeta and Wolfgang Nejdl
Multilingual pre-trained
language models such as XLM-R perform well for major
languages but struggle with low-resource Ge'ez-script
languages, largely because Latin-script-centric tokenizers split their words into many subwords. We introduce VEXMLM, a vocabulary-extended variant of XLM-R targeting Amharic and Tigrinya. We train
language-specific SentencePiece tokenizers on monolingual corpora, extend XLM-R's vocabulary with 30k Ge'ez-script subwords, and initialize each new
embedding to the mean of the pretrained
embeddings. VEXMLM undergoes two-stage training: (1) continued masked
language modeling on the monolingual corpora and (2) supervised fine-tuning on question answering and named entity recognition (Amharic and Tigrinya) and sentiment analysis (Amharic). VEXMLM lowers tokenizer fertility below that of XLM-R and Glot500 on both
languages, by 28.0% (Amharic) and 45.9% (Tigrinya) relative to XLM-R. Downstream, it modestly improves named entity recognition over XLM-R, scores below XLM-R on extractive question answering, and is comparable on sentiment analysis. An ablation on Tigrinya NER shows that vocabulary expansion alone lowers accuracy on out-of-vocabulary words (words that XLM-R's tokenizer cannot represent or splits into more pieces than the expanded tokenizer), and that continued pretraining is required for the expanded model to exceed the baseline. Vocabulary expansion thus makes Ge'ez-script tokenization substantially more efficient, while its downstream benefit depends on the task and on adapting the new
embeddings through continued pretraining. Resources: GitHub repository | Hugging Face model.
Read the full abstract ▾
Computation and Language
Mask-Aware Policy Gradients for Diffusion Language Models
Haran Raajesh, Kulin Shah, Adam Klivans et al. (+1 more)
Reinforcement learning has proven effective for improving
reasoning in large
language models, but extending it to Masked
Diffusion Language Models (MDLMs) remains challenging due to the intractability of the log-likelihood estimation. Existing approaches approximate this log-likelihood by modeling only the
token predictions, ignoring the order in which positions are unmasked during generation. We observe that MDLM generation involves two decisions at each step: what
tokens to place at each masked position and which positions to remask. We formalize this as a two-stage action MDP, showing that the policy gradient naturally decomposes into a
token term and a masking term. Combining optimization of both terms leads to state-of-the-art outcomes on mathematical
reasoning and coding
benchmarks, with scores of 87.1% on GSM8K and 53.4% on MBPP.
Read the full abstract ▾
All authors Haran Raajesh, Kulin Shah, Adam Klivans, Philipp Krähenbühl
Computation and Language
T^2MLR: Transformer with Temporal Middle-Layer Recurrence
Ziyang Cai, Xingyu Zhu, Yihe Dong et al. (+2 more)
Transformer reasoning is limited by autoregressive decoding, which repeat edly compresses rich hidden computation through
token space and makes it difficult for intermediate
reasoning states to persist across time. We in troduce
Transformers with Temporal Middle-Layer Recurrence (T2MLR), a
transformers-based latent
reasoning architecture that fuses a cached middle layer representation from the previous
token directly into an earlier layer of the current
token position, enabling abstract intermediate computation to persist across decoding steps with little inference overhead. Across natural-
language pretraining and multi-hop
reasoning finetuning, T2MLR consistently outperforms data- and parameter-matched
Transformer base lines. Moreover, applying recurrence to only a localized middle-layer block (as little as 20% of the network) often outperforms full-layer recurrence. Im portantly, T2MLR does not require pretraining from scratch: retrofitting the recurrent pathway into an existing pretrained 1.7B
Transformer and briefly finetuning substantially improves math
reasoning, lowering the barrier to practical adoption. These results suggest that effective latent
reasoning in
Transformers does not require looping over all layers as in previous works, but can instead emerge more strongly from targeted middle-layer recurrence.
Read the full abstract ▾
All authors Ziyang Cai, Xingyu Zhu, Yihe Dong, Yinghui He, Sanjeev Arora
Computation and Language · Cross-listed from cs.AI
Benchmarking Multimodal Large Language Models for Scientific Visualization Literacy
Patrick Phuoc Do, Chau M. Ta and Chaoli Wang
Multimodal large
language models (MLLMs) are increasingly used to interpret visualizations, yet current evaluations remain largely chart-centric and provide limited evidence of understanding of scientific visualization (SciVis). We
benchmark six MLLMs on the scientific visualization literacy assessment test, a standardized SciVis literacy assessment comprising 49 items based on 18 scientific visualizations and illustrations, spanning 8 techniques and 11 task types. We evaluate three closed-source and three open-source models under a closed-world protocol and compare their performance using data from 485 human participants. Results show that current MLLMs do not exhibit uniform SciVis literacy. Gemini is the strongest model overall, exceeding the human mean across the evaluated subsets, whereas the open-source models remain below the human baseline. Performance is highly uneven across techniques and tasks: models perform best on scientific illustration, search, and spatial understanding, but struggle on texture-based and integration-based visualizations and on quantitative estimation. Error analysis reveals recurring failures in fine-grained quantitative estimation, flow-direction interpretation, and grounded encoding interpretation. These findings position SciVis literacy as a necessary
benchmark dimension for evaluating
multimodal AI systems. Our code and model outputs are publicly available at https://github.com/patdmp/mllm-scivis-lit-
benchmark.
Read the full abstract ▾
Computation and Language
Linear representations of grammaticality in neural language models
Jane Li and Najoung Kim
Whether neural
language models (NLMs) possess the ability to distinguish strings on the basis of their grammaticality remains a debated topic in the computational linguistics literature. Existing evidence has largely relied on probability-based measures, testing whether models assign higher probabilities to grammatical than ungrammatical strings. However, probability comparisons have been criticized as a measure for grammatical knowledge based on the assumption that grammaticality is inherently entangled with likelihood. Model-assigned probability is a function of many related sentence properties, such as lexical frequency, plausibility, and world knowledge. In this work, we move beyond probability-based evaluations and investigate whether grammaticality is encoded in the internal representations of NLMs. Using mass-mean probing, we test whether grammatical and ungrammatical sentences are systematically separated in representational space. We further examine the extent to which these representations are independent of sentence properties that are correlated with grammaticality, as well as their generalization across grammatical phenomena and
languages. Our results provide evidence that grammaticality is robustly encoded in sentence representations of a wide range of pretrained NLMs, yielding clear representational separation on the dimension of grammaticality that cannot be fully explained by alternative sentence-level factors. Moreover, this encoding generalizes across a broad range of grammatical phenomena and to some degree, across
languages, suggesting that grammaticality constitutes a coherent representational dimension in contemporary NLMs. These findings contribute new evidence to debates about the nature of syntactic knowledge in
language models and offer a complementary framework for evaluating grammatical competence that is not dependent on string probabilities alone.
Read the full abstract ▾
Computation and Language · Cross-listed from cs.AI
MedFailBench: A Clinician-Built Open-Source Benchmark for Medical AI Safety Boundary Inspection
Goktug Ozkan
Most medical AI
benchmarks measure whether a model knows the correct answer. MedFailBench asks a different question: which safety boundary failed? We present a synthetic
benchmark and failure atlas built by a clinician. The resource labels medical AI errors by severity from 1 to 5 and safety gate type: missed urgent escalation, unsafe remote dosing, unsafe discharge reassurance, evidence fabrication, unsafe protocol execution, and source support gap. The current public release (v0.2.1) contains 44 synthetic cases reviewed by a clinician, with severity annotations, a public Hugging Face Space source, a safety gate taxonomy, a clinical severity rubric, and an automated pipeline for archiving model response screening runs. Forty cases have a populated safety gate field, and four require gate completion. No patient data, clinical validation claims, or model rankings are included. MedFailBench is released under Apache-2.0 and CC-BY-4.0 and carries the Zenodo DOI 10.5281/zenodo.21205535.
Read the full abstract ▾
Computation and Language · Cross-listed from cs.LG
Byeongho Heo, Jaehui Hwang, Sangdoo Yun et al. (+1 more)
On-policy
distillation is an alternative post-training method in reinforcement learning that alleviates the constraints imposed by reward models by providing
token-level supervision from a teacher model. Although on-policy
distillation has been studied and applied across various settings, its fundamental design remains underexplored. In this paper, we introduce a new
distillation reward, termed the delta signal, instead of directly imitating the teacher's output distribution. The delta signal is defined as the difference between the teacher model and its base model prior to instruction tuning for
reasoning capability. It therefore captures the changes induced by
reasoning tuning and provides a more direct signal for transferring
reasoning capabilities. Using extensive empirical evidence, we show that the delta signal substantially improves on-policy
distillation and refer to the new
distillation method as On-Policy Delta
Distillation (OPD$^2$). Experiments across mathematics, science, and code-
reasoning benchmarks demonstrate that OPD$^2$ consistently outperforms conventional on-policy
distillation, enabling
reasoning LLMs to achieve strong performance with only a short post-training period. Code will be available at https://github.com/naver-ai/opd2
Read the full abstract ▾
All authors Byeongho Heo, Jaehui Hwang, Sangdoo Yun, Dongyoon Han
Computation and Language
Grokipedia vs Wikipedia: An LLM-Based Audit of Political Neutrality along Ideologies
Filippos Vlahos, Guillaume Bied and Tijl De Bie
Online encyclopedias shape political opinion and, through it, democratic discourse. In late 2025, Grokipedia was released, an encyclopedia written entirely by the LLM Grok. One motivation behind the project was to provide an unbiased alternative to Wikipedia, which has faced accusations of "left-wing" and "liberal" bias. But does an encyclopedia written by an LLM deliver greater neutrality, or does it simply embed a different ideology? We conduct a large-scale political bias study on Grokipedia and Wikipedia, analysing 1,394 article pairs describing members of government for neutrality along nine expert-coded ideology dimensions employing four LLM judges, Grok, Claude, Mistral, and DeepSeek. As the LLMs could themselves be biased, we also investigate patterns in their judgments. We find all LLM-judges, including Grok, to rate Grokipedia less neutral than Wikipedia. Both encyclopedias are rated as portraying politicians favourably overall, but towards different ideological groups. Grokipedia particularly favours economically right-wing politicians and penalises socially liberal ones, while Wikipedia is rated as favourably biased towards the latter.
Read the full abstract ▾
Computation and Language
Digital Pantheon: Simulating and Auditing Coalition Formation with LLM Agents
Dylan Van Mulders, Matthias Bogaert and Dirk Van den Poel
The formation of political coalitions is a complex negotiation driven by both concrete policy objectives and deep-seated ideological convictions. While Large
Language Models (LLMs) open new avenues for computational political science, the neutrality and helpfulness biases instilled by Reinforcement Learning from Human Feedback (RLHF) prevent them from sustaining steadfast partisan behaviour. We present a multi-
agent framework that reconciles factual grounding with ideological
alignment by combining Supervised Fine-Tuning (SFT), Direct Preference Optimization (DPO), and
Retrieval-Augmented Generation (RAG): DPO instils aggressive party-specific personas, while a per-party RAG pipeline keeps each
agent bounded to its official manifesto. We operationalize the framework on the 2019 Flemish election, deploying the partisan
agents in a hub-and-spoke negotiation arbitrated by a formateur. To make the emergent negotiation interpretable, we introduce a Multi-Layered Information Lineage
Topology (MILT) that traces every clause in the final agreement back to its manifesto origin and classifies it into five provenance states, a Coalition Influence Score (CIS) that aggregates these traceable contributions to identify which party shaped the agreement, and a real-world grounding pass that
benchmarks each simulated provision against the historically adopted coalition agreement. Across three independent simulations the framework yields a stable winner and ranking (N-VA ahead of CD&V and Open Vld), and manifesto-anchored lineage reliably predicts real-world materialization whereas hallucinated content does not. The result is a transparent, scalable testbed for the ex-ante exploration of party compatibility and formateur-mediated compromise.
Read the full abstract ▾
Computation and Language
Rubrics on Trial: Evolving Rubrics from a Single Query via Synthetic Pairwise Evidence
Haocheng Yang, Licheng Pan, Yuan Lu et al. (+7 more)
Rubric
evolution offers a promising approach to improving the quality of rubrics generated by large
language models (LLMs). Central to this process is rubric comparison, which identifies the better of two rubrics and guides the direction of
evolution. However, accurate rubric comparison is difficult, which presents two challenges. (1) It should reflect downstream task performance, which is essential for assessing rubric utility but often prohibitively expensive to evaluate. (2) It should discourage unnecessary criteria, which increase verification costs and may dilute the influence of essential criteria. To address these challenges, we introduce Rubrics on Trial, a multi-
agent framework that evolves rubrics by comparing synthetic response pairs. To address challenge 1, the framework compares synthetic responses that satisfy the respective rubrics, providing a proxy for downstream performance without training a separate policy for each rubric. To address challenge 2, it assesses the necessity of a candidate criterion by independently generating high-quality alternative responses that violate it and comparing them with edited versions that satisfy it. A rubric is favored when it improves response quality in both comparisons, and the resulting comparison signal is further incorporated for rubric
evolution. Extensive experiments demonstrate that Rubrics on Trial improves the quality of generated rubrics and leads to better downstream task performance.
Read the full abstract ▾
All authors Haocheng Yang, Licheng Pan, Yuan Lu, Xiaoxi Li, Zhichao Chen, Chunyuan Zheng, Shuai Shao, Haoxuan Li, Hao Wang, Kun Zhang
Computation and Language
OmniaBench: Benchmarking General AI Agents Across Diverse Scenarios
Chengyu Shen, Yujie Fu, Gangtao Xin et al. (+13 more)
Large
language models are increasingly evolving from text generators into general
agents capable of understanding user requests, invoking external tools, and completing complex tasks through interaction. However, existing
agent benchmarks often focus on limited scenarios, tool ecosystems, or interaction formats, making it difficult to systematically characterize model capabilities across heterogeneous application settings. We introduce OmniaBench, a
benchmark for evaluating general
agents across diverse scenarios with explicit state spaces. We derive application-oriented scenario knowledge from app stores, product documents, industry resources, Web
retrieval, and human refinement, forming a hierarchical taxonomy that spans ToC, ToB and ToE with 90 level-1 and 354 level-2 domains. Based on this taxonomy, we construct executable environments and synthesize single-turn and multi-turn tasks through four complementary routes: DAG, DAG-S, Solver, and Program. OmniaBench further introduces a ten-dimensional capability taxonomy and eight compositional atomic difficulty factors to support fine-grained evaluation and analysis. The resulting
dataset contains 1,431 tasks, together with a challenging subset of 644 tasks designed to reduce evaluation cost and mitigate potential contamination of the full set after public release. The bench presents substantial challenges to current frontier models, with even Claude-Sonnet-5 and GPT-5.6-Sol achieving Overall Pass@1 scores of only 58.54 and 57.14, respectively. Further analyses reveal clear differences across domains and capabilities, as well as persistent limitations in planning, constraint maintenance, and adaptive correction. OmniaBench provides a broad and diagnostic
benchmark for characterizing the capability boundaries of general
agents.
Read the full abstract ▾
All authors Chengyu Shen, Yujie Fu, Gangtao Xin, Yanheng Hou, Wenlong Fei, Guojie Zhu, Jiawei Li, Hongcheng Gao, Runming He, Zhen Hao Wong, Meiyi Qiang, Hao Liang, Zhao Cao, Hao Jiang, Chong Chen, Wentao Zhang
Computation and Language
Latent Trajectory Discrimination for AI-Generated Text Detection
Gianluca Bonifazi, Christopher Buratti, Michele Marchetti et al. (+5 more)
Most existing approaches to AI-Generated Text Detection (AIGTD) treat documents as static objects and base their decisions on aggregate statistics or globally compressed
embeddings. However, this perspective overlooks the inherently dynamic nature of autoregressive generation, where content evolves progressively through the latent space. In this paper, we reformulate AIGTD as the problem of distinguishing between latent generation trajectories. Instead of relying on static representations, we model how textual representations evolve across the sequence. To this end, we propose
Geometric Trajectory and Contrastive Learning (GTCL), a framework that segments the document into ordered local units, encodes each unit in an
embedding space, and constructs a structured and sequence-level representation. GTCL then applies contrastive learning to these trajectories to learn
geometric regularities associated with the autoregressive generation. Evaluations performed on three different
benchmarks and several approaches show that GTCL outperforms detection baselines consistently, which implies that explicitly modeling sequential dynamics provides robust discriminative signals across models and domains. These results suggest that modeling trajectory differences could improve detection and open up a dynamic direction that has been underexplored in previous AIGTD literature.
Read the full abstract ▾
All authors Gianluca Bonifazi, Christopher Buratti, Michele Marchetti, Federica Parlapiano, Giulia Quaglieri, Davide Traini, Domenico Ursino, Luca Virgili
Computation and Language
Show Me How You Reason and I'll Tell You Who You Are: Reasoning Graphs for Robust LLM Authorship Attribution
Zlata Kikteva, Artur Romazanov, Annette Hautli-Janisz et al. (+1 more)
Given the current trend to employ large
language models (LLMs) in almost any imaginable context, LLM-generated text detection and authorship attribution have become a pressing issue. Prior work has primarily focused on surface-level linguistic features, an approach shown to be susceptible to paraphrasing and other obfuscation techniques. In this paper, we go beyond the linguistic surface, extracting and analysing
reasoning structures in LLM-generated texts with the goal of capturing more complex signals of LLM authorship. We propose a graph neural network approach that leverages
reasoning graphs extracted by an argument mining pipeline, demonstrating improved robustness and generalisation over a traditional Longformer baseline. Our approach outperforms the baseline by up to 27 percentage points under the obfuscation attacks such as paraphrasing and backtranslation, and 19 percentage points when evaluated on the texts generated by the unseen model versions, simulating real-world conditions in which new LLM versions are continuously released.
Read the full abstract ▾
All authors Zlata Kikteva, Artur Romazanov, Annette Hautli-Janisz, Ramon Ruiz-Dolz
Computation and Language · Cross-listed from cs.LG
Leveraging Instruction Tuning and Merging for Reasoning Model Adaptation
Yu-Du Feng, Niels Mündler-Sasahara, Mark Vero et al. (+1 more)
Reasoning language models (RLMs) demonstrate impressive performance by leveraging test-time compute in the form of
reasoning tokens. However, this behavior makes adapting RLMs to new domains challenging and expensive. The reason is that further training can disturb the learned behavior and degrade model performance. This makes it difficult to leverage supervised fine-tuning data with human-written solutions: although it contains high-quality annotations, it lacks
reasoning tokens. In this work, we show how, despite this challenge, such data can be used efficiently for RLM adaptation. For this, we first use standard instruction tuning. Next, we leverage model merging to combine the instruction-tuned model with the original RLM, picking the merging ratio such that the resulting model's
reasoning behavior on the target domain is recovered. We evaluate our method across four RLMs on coding and text summarization tasks, where it improves target-task performance by up to $11.0\%$ while preserving
reasoning behavior and limiting the out-of-distribution score degradation to on average $0.7\%$. Importantly, our adaptations are efficient and economical, costing less than USD $\$10$ per model.
Read the full abstract ▾
All authors Yu-Du Feng, Niels Mündler-Sasahara, Mark Vero, Martin Vechev
Computation and Language · Cross-listed from cs.LG
Innocuous-Seeming Data, Latent Ideology: Ideological Generalisation in Finetuned LLMs
Robert Graham, Edward Stevinson and Yariv Barsheshat
Finetuning
language models on small, curated
datasets is standard practice for adapting them to specific policies or domains. We show that finetuning on narrow, factually-defensible, moderation-passing data can cause broad ideological shifts across unrelated domains, while preserving general capabilities. Training GPT-4.1 on right- or left-leaning economics Q&A yields matched ideological shifts on topics such as criminal justice, the environment, and cultural taste. The same effect appears with plausibly-deployed
datasets such as workplace HR policy and practical finance queries, as well as on a science-pseudoscience axis where food-safety finetuning increases sycophantic agreement with users expressing false health beliefs. We call this phenomenon ideological generalisation and propose a methodology to measure two properties: breadth, how far the shift reaches across topics absent from training, and amplification, how much finetuning intensifies the shift relative to few-shot prompting on the same examples. We show that few-shot prompting indicates the direction of generalisation but finetuning pushes the model to further extremes, including to far out-of-distribution outputs such as endorsements of race-IQ connections and political violence. The effect replicates on Gemma-3, holds under judge-free evaluations and external
benchmarks, survives mixing with generic data, and leaves GSM8K accuracy within $\pm 1$pp of the baseline.
Read the full abstract ▾
Computation and Language · Cross-listed from cs.IR
Does generative AI supersede supervised XMLC? A Benchmark Study on Automated Subject Indexing with German Scientific Literature
Maximilian Kähler, Katja Konermann, Lisa Kluge et al. (+1 more)
With a large controlled vocabulary as the label set, the task of automated subject indexing in a library can be understood as a multi-label classification task. If the set of subject terms is large, the problem fits the Extreme Multi-Label Classification (XMLC) objective. In this study, we apply a selection of specialised supervised XMLC methods to the test case of subject indexing contemporary German scientific literature, collected at the German National Library (DNB). We contrast these results by including a classical lexical matching baseline and three of our own recently developed LLM-based methods into the
benchmark.
Algorithms are evaluated and compared in several metrics. This includes binary relevance comparisons with previously indexed material, as well as graded relevance ratings by professional subject librarians. A challenge for all methods is to reliably make suggestions from the long tail of the subject vocabulary. We find that supervised XMLC
algorithms relying on
transformer-based dense features give best results in terms of overall binary relevance metrics. However, focusing on graded relevance and performance in the long tail of our subject vocabulary, the LLM-based generative methods give better results, making them a promising alternative for future productive use.
Read the full abstract ▾
All authors Maximilian Kähler, Katja Konermann, Lisa Kluge, Markus Schumacher
Computation and Language · Cross-listed from cs.MA
The Energy Society: A Simulation Environment for Studying Agent Cooperation under Survival Pressure
Lucas Bergholdt Hansen, Federico Torrielli, Filippo Tonini et al. (+1 more)
LLM-based
agents are increasingly deployed in multi-
agent environments whose incentives can shape their behavior. We introduce The Energy Society, a minimal survival economy for studying how competitive and cooperative incentives affect emergent behavior when inference cost is directly tied to survival:
Agents spend energy based on model size when generating
tokens, regain energy by completing jobs or receiving donations, and deactivate if their energy reaches zero. We compare competitive and cooperative objectives against a baseline setting and several control variants. Across experiments, larger models consistently consume the most energy and spend more energy than they gain, even in those settings where
token cost is not size-dependent. Cooperative incentives substantially alter behavior:
agents donate to reactivate others, sometimes at the cost of their own survival, and job allocation changes. Ablations reveal that allowing
agents to recommend actions to each other supports coordination and ambitious job selection, while
memory helps
agents calibrate risk from past outcomes.
Agents rarely choose direct sabotage, but show more subtle signs of self-serving behavior in the competitive setting. The Energy Society is a compact testbed for studying the interaction between
token costs and group incentives under a survival pressure. Source code is available at https://github.com/LucasBergholdt/EnergySociety
Read the full abstract ▾
All authors Lucas Bergholdt Hansen, Federico Torrielli, Filippo Tonini, Lukas Galke Poech
Computation and Language
SEED: Self-Evolving On-Policy Distillation for Agentic Reinforcement Learning
Jinyang Wu, Shuo Yang, Zhengxi Lu et al. (+8 more)
Large
language models are increasingly trained as interactive
agents for long-horizon tasks involving multi-turn interaction, tool use, and environment feedback. Outcome-based reinforcement learning (RL) provides a practical optimization paradigm, but its sparse trajectory-level rewards offer limited guidance on intermediate decisions, leaving a supervision gap between episode-level outcomes and
token-level policy learning. We propose SEED (SElf-Evolving On-Policy
Distillation), a self-evolving framework that converts completed on-policy trajectories into training-time hindsight skills and distills their behavioral effect back into the policy model. SEED first fine-tunes the policy to analyze completed trajectories and generate natural-
language skills that capture reusable workflows, decisive observations, or failure-avoidance rules. During RL, the current policy both collects trajectories and serves as the analyzer that extracts hindsight skills from them. Policy updates therefore improve subsequent decision making and skill analysis together, allowing hindsight supervision to evolve with the policy. SEED then re-scores the sampled actions under ordinary and skill-augmented contexts, converting the skill-induced probability shift into a dense
token-level on-policy
distillation signal. This signal is jointly optimized with outcome-based RL, keeping the auxiliary supervision aligned with the current trajectory distribution. Extensive experiments on text-based and
vision-based agentic tasks show that SEED consistently improves performance and sample efficiency, exhibiting robust generalization to unseen scenarios. Our code is available at https://github.com/jinyangwu/SEED.
Read the full abstract ▾
All authors Jinyang Wu, Shuo Yang, Zhengxi Lu, Fan Zhang, Yuhao Shen, Lang Feng, Haoran Luo, Zheng Lian, Shuai Zhang, Zhengqi Wen, Jianhua Tao
Computation and Language
Dialogue Summarization with Emotion Dynamics Using Topic- and Participant-Centric Decomposition
Linyun Xiang, Mark Neerincx and Stephanie Tan
Existing text summarization research has focused much on monologic information (e.g., newspaper articles, reports) without accounting for the interaction between speakers or authors. In contrast, dialogues are a rich communication channel where multiple participants conduct back and forth exchanges to construct meaning. We propose a dialogue summarization framework that explicitly models both semantic and
emotion dynamics using
multimodal dialogue inputs, built on an adapted hierarchical Chain-of-
Agents approach. We decompose dialogues from two perspectives: (1) topic segments based on the utterances of all participants, and (2) participant-specific utterance segments. These are used to generate corresponding summaries while incorporating automatically inferred
emotions. Topic- and participant-level summaries are aggregated into a dialogue summary capturing semantic content and
emotion trajectories. To evaluate beyond content accuracy, we introduce
emotion trajectory metrics measuring how well summaries preserve emotional flow. Experiments with small
language models on
multimodal dialogue
datasets show that our framework produces summaries with both semantic and
emotion content. Further experiments on explicit
emotion label availability highlight the efficacy of our proposed methodology and the opportunities in dialogue analysis using
language models.
Read the full abstract ▾
Computation and Language
CoTu at EXACT 2026: Neuro-Symbolic Reasoning for Transparent Educational QA
Quoc-Khang Tran, Minh-Thien Nguyen, Phu-An Thai et al. (+3 more)
Transparent educational question answering asks for answers that are not only correct but explainable, and doing so with small models rules out the
reasoning power of the largest proprietary systems. The EXACT 2026 competition poses this problem concretely: open-weight
language models of at most 8B parameters, self-hosted, with a natural-
language explanation for every answer. It pairs two tasks: logical
reasoning over university regulations, and multi-step physics problem solving. We describe the system that team \cotu{} developed to address both, a neuro-symbolic Program-of-Thought pipeline in which a 4B backbone writes a program rather than stating an answer directly: for regulation queries it emits a Z3 encoding whose entailment verdict grounds the deduction, and for physics it emits numerical Python, both wrapped in a shared self-correction loop and a unified explained-JSON output. Answer-type routing,
distillation-based task fine-tuning, and a latency-aware serving stack – SGLang with speculative decoding – keep the system within the 60-second per-query limit. The system achieved a perfect score on the physics task in both automated selection rounds and obtained the highest final-round technical score of any team – $13.44/15$, combining automated answer evaluation with expert-judged
reasoning depth – with the equally weighted presentation score included, \cotu{} placed 3rd overall. Grounding answers in a symbolic solver yields correct, verifiable deductions at the 4B scale, and the residual difficulty lies in premise selection rather than the deduction itself.
Read the full abstract ▾
All authors Quoc-Khang Tran, Minh-Thien Nguyen, Phu-An Thai, Xuan-Tung Bui, Truong-Thanh Ma, Nguyen-Khang Pham
Computation and Language
The Misclassification of Autistic Writing as AI-Generated
Summer Chambers and Matthew C. Kelley
Recent findings suggest that detection models for artificial intelligence (AI) cannot accurately identify AI-generated text and may exhibit bias against certain minority groups. In the present study, anecdotal claims that autistic writers more often have their work flagged as AI-generated are examined empirically. A corpus of approximately 60,000 Reddit posts split into "likely-autistic" and "general-Reddit" subcorpora is used to compare the distribution of probabilities output by the OpenAI GPT-2 detection model. Differences in textual features between subcorpora are observed and compared to reported features of AI-generated text. Results showed that while less than two-percent of either subcorpus was flagged as AI-generated by the model, significantly more texts from the likely-autistic subcorpus were flagged. Connections between features of text with likely-autistic authors and AI-generated text were not straightforward. The widespread use of AI-detection models with a potential bias against autistic writers in their output
prompts ethical scrutiny, and the authors recommend further critical examination of the models themselves as well as their use in academic contexts.
Read the full abstract ▾
Computation and Language · Cross-listed from econ.GN
Does Multi-Agent Debate Improve AI Feedback on Research Papers?
Tomas Havranek and Zuzana Irsova
Probably not, at least for meta-analyses in economics. In a pre-registered, identity-masked, within-paper experiment, the authors of 44 meta-analyses ranked three AI reports on their own paper by usefulness for improving it: a single pass by a frontier model against two multi-
agent debate tools we built and expected to win. All reports were held to a common length and template. The authors preferred the single pass, by 0.66 rank points over mad-research (95% CI 0.32 to 1.00) and 0.57 over paper-workshop (0.16 to 0.95), though paper-workshop spent roughly thirty times the
tokens. Authors who recalled their journal referee report usually placed it first and never last; in a separate exercise, three AI judges almost always placed the real journal referee report last. Among the three AI reports, Gemini (the judge whose model family wrote none of the reports) would have ranked paper-workshop first in the authors' place, reversing the single-pass preference. The reversal warns against substituting an AI judge for the author. We measure perceived usefulness for finished papers; whether AI should referee papers is a separate question.
Read the full abstract ▾
Computation and Language
Gold-Guided Programmatic Distillation for Financial Reasoning over Hybrid Tables and Text
Yun Dong, Erica Zhao and Elana Chen
Financial question answering over hybrid tabular and textual data may require multi-source
reasoning and precise numerical computation. While large
language models (LLMs) can generate intermediate
reasoning steps, natural-
language rationales remain prone to arithmetic errors, making them an unreliable supervision source for
distillation. Building on programmatic
distillation, we develop an approach that transfers reliable numerical
reasoning from a large teacher model to a compact student using execution-verified Python programs instead of free-form textual rationales. It leverages gold derivations to guide teacher-side program synthesis and retains only programs that execute correctly and produce the gold answer, ensuring high-quality supervision. We further introduce an iterative recovery stage that revisits teacher-failed examples, enabling the student to recover and incorporate newly verified programs into training. Experiments on TAT-QA show that our framework is highly effective for hybrid financial
reasoning. Our best 7B student achieves 87.00 EM / 87.18 F1 on the test set, substantially outperforming the 72B teacher (78.46 EM) as well as traditional and strong LLM-based baselines, including TAGOP and TAT-LLM. These results demonstrate that execution-verified programmatic
distillation provides an effective and extensible framework for training smaller models to perform reliable numerical
reasoning.
Read the full abstract ▾