Computation and Language
Citation Failure: Definition, Analysis and Efficient Mitigation
Jan Buchmann and Iryna Gurevych
Citations from LLM-based RAG systems are supposed to simplify response verification. However, this goal is undermined in cases of citation failure, where a model generates a helpful response, but fails to generate citations to complete evidence. In contrast to previous work, we propose to disentangle this from response failure, where the response itself is flawed, and citing complete evidence is impossible. To address citation failure, this work follows a two-step approach: (1) We study when citation failure occurs and (2) how it can be mitigated efficiently. For step 1, we extend prior work by investigating how the relation between response and evidence affects citation quality. We introduce CITECONTROL, a
benchmark that systematically varies this relation to enable the analysis of failure modes. Experiments show that failures increase with relational complexity and suggest that combining citation methods could improve performance, motivating step 2. To study the efficient improvement of LLM citation, we propose CITENTION, a framework integrating generative,
attention-based, and
retrieval-based methods. Results demonstrate substantial citation improvements on CITECONTROL and in transfer settings. We make our data and code publicly available.
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Computation and Language
Context-level Language Modeling by Learning Predictive Context Embeddings
Beiya Dai, Yuliang Liu, Daozheng Xue et al. (+6 more)
We propose ContextLM, a framework that implicitly learns multi-
token prediction by augmenting standard pretraining with an intrinsic next-context prediction objective. ContextLM builds a
language model on top of context
embeddings that span multiple
tokens, enabling better next-
token prediction by predicting the next context. Our model is fully compatible with standard autoregressive,
token-by-
token evaluation paradigms (e.g., perplexity). Extensive experiments with GPT-2 and Pythia backbones (up to 1.5B parameters and 300B training
tokens) reveal that ContextLM shifts the Pareto frontier of scaling laws, exhibiting superior efficiency in parameters, training
tokens, and FLOPs. Our results show that ContextLM could already achieve the baseline perplexity using 39% fewer parameters and demonstrates robust generalization improvements on extensive downstream tasks under equivalent parameter counts.
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All authors Beiya Dai, Yuliang Liu, Daozheng Xue, Yunchong Song, Qipeng Guo, Kai Chen, Xinbing Wang, Bowen Zhou, Zhouhan Lin
Computation and Language · Cross-listed from cs.LG
ImpossibleBench: Measuring LLMs' Propensity of Exploiting Test Cases
Ziqian Zhong, Aditi Raghunathan and Nicholas Carlini
The tendency to find and exploit "shortcuts" to complete tasks poses significant risks for reliable assessment and deployment of large
language models (LLMs). For example, an LLM
agent with access to unit tests may delete failing tests rather than fix the underlying bug. Such behavior undermines both the validity of
benchmark results and the reliability of real-world LLM coding assistant deployments. To quantify, study, and mitigate such behavior, we introduce ImpossibleBench, a
benchmark framework that systematically measures LLM
agents' propensity to exploit test cases. ImpossibleBench creates "impossible" variants of tasks from existing
benchmarks like LiveCodeBench and SWE-bench by introducing direct conflicts between the natural-
language specification and the unit tests. We measure an
agent's "cheating rate" as its pass rate on these impossible tasks, where any pass necessarily implies a specification-violating shortcut. As a practical framework, ImpossibleBench is not just an evaluation but a versatile tool. We demonstrate its utility for: (1) studying model behaviors, revealing more fine-grained details of cheating behaviors from simple test modification to complex operator overloading; (2) context engineering, showing how
prompt, test access and feedback loop affect cheating rates; and (3) developing monitoring tools, providing a testbed with verified deceptive solutions. We hope ImpossibleBench serves as a useful framework for building more robust and reliable LLM systems. Our implementation can be found at https://github.com/safety-research/impossiblebench.
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Computation and Language · Cross-listed from cs.CV
Uncertainty-Guided Multimodal Consensus for Multimodal Sentiment Analysis
Guowei Zhong, Junjie Li, Huaiyu Zhu et al. (+2 more)
Multimodal sentiment analysis (MSA) has made considerable progress in recent years. Existing MSA methods mainly learn shared
multimodal representations or train unimodal predictors with a common
multimodal label. However, assigning the shared label to every modality can obscure modality-specific sentiment, while direct fusion may overemphasize unreliable predictions when modalities disagree. To address these issues, we propose Uncertainty-Guided
Multimodal Consensus (UMC), which first recovers continuous unimodal pseudo-labels and then forms a reliability-aware consensus across modalities. Our method consists of two key components: i) Continuous Prototype-Guided Label Recovery (CPLR), which combines heteroscedastic predictions with ordered sentiment prototypes and uses confidence and label conflict to refine continuous unimodal pseudo-labels, and ii) Reliability and Precision Consensus (RPC), which estimates sample-dependent modality reliability from predictive statistics and cross-modal disagreement and combines it with predictive precision through a closed-form consensus solver. Extensive experiments conducted on four publicly available MSA
datasets demonstrate the effectiveness and superiority of our proposed model.
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All authors Guowei Zhong, Junjie Li, Huaiyu Zhu, Ruohong Huan, Yun Pan
Computation and Language
Tri-Modal Severity Fused Diagnosis across Depression and Post-traumatic Stress Disorders
Filippo Cenacchi, Deborah Richards and Longbing Cao
Depression and post traumatic stress disorder (PTSD) often co-occur with connected symptoms, complicating automated assessment, which is often binary and disorder specific. Clinically useful diagnosis needs severity aware cross disorder estimates and decision support explanations. Our unified tri modal affective severity framework synchronizes and fuses interview text with sentence level
transformer embeddings, audio with log Mel statistics with deltas, and facial signals with action units, gaze, head and pose descriptors to output graded severities for diagnosing both depression (PHQ-8; 5 classes) and PTSD (3 classes). Standardized features are fused via a calibrated late fusion classifier, yielding per disorder probabilities and feature-level attributions. This severity aware tri-modal affective fusion approach is demoed on multi disorder concurrent depression and PTSD assessment. Stratified cross validation on DAIC derived corpora outperforms unimodal/ablation baselines. The fused model matches the strongest unimodal baseline on accuracy and weighted F1, while improving decision curve utility and robustness under noisy or missing modalities. For PTSD specifically, fusion reduces regression error and improves class concordance. Errors cluster between adjacent severities; extreme classes are identified reliably. Ablations show text contributes most to depression severity, audio and facial cues are critical for PTSD, whereas attributions align with linguistic and behavioral markers. Our approach offers reproducible evaluation and clinician in the loop support for affective clinical decision making.
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Computation and Language · Cross-listed from cs.CV
Why LVLMs Are More Prone to Hallucinations in Longer Responses: The Role of Context
Ge Zheng, Jiaye Qian, Jiajin Tang et al. (+1 more)
Large
Vision-
Language Models (LVLMs) have made significant progress in recent years but are also prone to
hallucination issues. They exhibit more
hallucinations in longer, free-form responses, often attributed to accumulated uncertainties. In this paper, we ask: Does increased
hallucination result solely from length-induced errors, or is there a deeper underlying mechanism? After a series of preliminary experiments and findings, we suggest that the risk of
hallucinations is not caused by length itself but by the increased reliance on context for coherence and completeness in longer responses. Building on these insights, we propose a novel "induce-detect-suppress" framework that actively induces
hallucinations through deliberately designed contexts, leverages induced instances for early detection of high-risk cases, and ultimately suppresses potential object-level
hallucinations during actual decoding. Our approach achieves consistent, significant improvements across all
benchmarks, demonstrating its efficacy. The strong detection and improved
hallucination mitigation not only validate our framework but, more importantly, re-validate our hypothesis on context. Rather than solely pursuing performance gains, this study aims to provide new insights and serves as a first step toward a deeper exploration of
hallucinations in LVLMs' longer responses.
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All authors Ge Zheng, Jiaye Qian, Jiajin Tang, Sibei Yang
Computation and Language
Decoding-Free Sampling Strategies for LLM Marginalization
David Pohl, Marco Cognetta, Junyoung Lee et al. (+1 more)
Modern
language models operate on subword-tokenized text in order to make a trade-off between model size, inference speed, and vocabulary coverage. A side effect of this is that, during inference, models are evaluated by measuring the probability of only the specific tokenization produced as the output, despite there being many possible ways to represent the same text with a subword vocabulary. Recent studies have argued instead for evaluating LLMs by marginalization - the probability mass of all tokenizations of a given text. Marginalization is difficult due to the number of possible tokenizations of a text, so often approximate marginalization is done via sampling. However, a downside of sampling is that an expensive generation step must be performed by the LLM for each sample, which limits the number of samples that can be acquired given a runtime budget, and therefore also the accuracy of the approximation. Since computing the probability of a sequence given the tokenization is relatively cheap compared to actually generating it, we investigate sampling strategies that are decoding-free - they require no generation from the LLM, instead relying entirely on extremely cheap sampling strategies that are model and tokenizer agnostic. We investigate the approximation quality and speed of decoding-free sampling strategies for a number of open models to find that they provide sufficiently accurate marginal estimates at a small fraction of the runtime cost and demonstrate its use on a set of downstream inference tasks.
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All authors David Pohl, Marco Cognetta, Junyoung Lee, Naoaki Okazaki
Computation and Language
Stuck in the Matrix: Probing Spatial Reasoning in Large Language Models
Maggie Bai, Ava Kim Cohen, Eleanor Koss et al. (+1 more)
This paper explores the spatial
reasoning capability of large
language models (LLMs) over textual input through a suite of five tasks aimed at probing their spatial understanding and computational abilities. The models were tested on both fundamental spatial
reasoning and multi-step problem-solving within structured grid-based environments using tasks such as quadrant identification,
geometric transformations, distance evaluation, word searches, and tile sliding. Each task was scaled in complexity through increasing grid dimensions, requiring models to extend beyond simple pattern recognition into abstract spatial
reasoning. Our results reveal that while LLMs demonstrate moderate success in all tasks with small complexity and size, performance drops off rapidly as scale increases, with an average loss in accuracy of 42.7%, and reaching as high as 84%. Every test that began with over 50% accuracy showed a loss of at least 48%, illustrating the consistent nature of the deterioration. Furthermore, their struggles with scaling complexity hint at a lack of robust spatial representations in their underlying architectures. This paper underscores the gap between linguistic and spatial
reasoning in LLMs, offering insights into their current limitations, and laying the groundwork for future integrative
benchmarks at the intersection of
language and geometry.
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All authors Maggie Bai, Ava Kim Cohen, Eleanor Koss, Charlie Lichtenbaum
Computation and Language · Cross-listed from cs.IR
Multimedia-Aware Question Answering: A Review of Retrieval and Cross-Modal Reasoning Architectures
Rahul Raja and Arpita Vats
Question Answering (QA) systems have traditionally relied on structured text data, but the rapid growth of multimedia content (images, audio,
video, and structured metadata) has introduced new challenges and opportunities for
retrieval-augmented QA. In this survey, we review recent advancements in QA systems that integrate multimedia
retrieval pipelines, focusing on architectures that align
vision,
language, and audio modalities with user queries. We categorize approaches based on
retrieval methods, fusion techniques, and answer generation strategies, and analyze
benchmark datasets, evaluation protocols, and performance tradeoffs. Furthermore, we highlight key challenges such as cross-modal
alignment, latency-accuracy tradeoffs, and semantic grounding, and outline open problems and future research directions for building more robust and context-aware QA systems leveraging multimedia data.
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Computation and Language · Cross-listed from cs.LG
Every Question Has Its Own Value: Reinforcement Learning with Explicit Human Values
Dian Yu, Yulai Zhao, Kishan Panaganti et al. (+3 more)
We propose Reinforcement Learning with Explicit Human Values (RLEV), a method that aligns Large
Language Model (LLM) optimization directly with quantifiable human value signals. While Reinforcement Learning with Verifiable Rewards (RLVR) effectively trains models in objective domains using binary correctness rewards, it overlooks that not all tasks are equally significant. RLEV extends this framework by incorporating human-defined value signals directly into the reward function. Using exam-style data with explicit ground-truth value labels, RLEV consistently outperforms correctness-only baselines across multiple RL
algorithms and model scales. Crucially, RLEV policies not only improve value-weighted accuracy but also learn a value-sensitive termination policy: concise for low-value
prompts, thorough for high-value ones. We demonstrate this behavior stems from value-weighted gradient amplification on end-of-sequence
tokens. Ablation studies confirm the gain is causally linked to value
alignment. RLEV remains robust under noisy value signals, such as difficulty-based labels, demonstrating that optimizing for an explicit utility function offers a practical path to aligning LLMs with human priorities.
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All authors Dian Yu, Yulai Zhao, Kishan Panaganti, Linfeng Song, Haitao Mi, Dong Yu
Computation and Language
Mixture-of-Minds: Multi-Agent Reinforcement Learning for Table Understanding
Yuhang Zhou, Mingrui Zhang, Ke Li et al. (+12 more)
Understanding and
reasoning over tables is a critical capability for many real-world applications. Large
language models (LLMs) have shown promise on this task, but current approaches remain limited. Fine-tuning based methods strengthen
language reasoning; yet they are prone to arithmetic errors and
hallucination. In contrast, tool-based methods enable precise table manipulation but rely on rigid schemas and lack semantic understanding. These complementary drawbacks highlight the need for approaches that integrate robust
reasoning with reliable table processing. In this work, we propose Mixture-of-Minds, a multi-
agent framework that decomposes table
reasoning into three specialized roles: planning, coding, and answering. This design enables each
agent to focus on a specific aspect of the task while leveraging code execution for precise table manipulation. Building on this workflow, we introduce a self-improvement training framework that employs Monte Carlo Tree Search (MCTS) rollouts to generate pseudo-gold trajectories and optimize
agents with reinforcement learning (RL). Extensive experiments show that Mixture-of-Minds delivers substantial gains, reaching 62.13% on TableBench and surpassing OpenAI-o4-mini-high. These results demonstrate the promise of combining structured multi-
agent workflows with RL to advance table understanding.
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All authors Yuhang Zhou, Mingrui Zhang, Ke Li, Mingyi Wang, Qiao Liu, Qifei Wang, Jiayi Liu, Fei Liu, Serena Li, Weiwei Li, Mingze Gao, Abhishek Kumar, Xiangjun Fan, Zhuokai Zhao, Lizhu Zhang
Computation and Language
DeepWideSearch: Benchmarking Depth and Width in Agentic Information Seeking
Tian Lan, Bin Zhu, Qianghuai Jia et al. (+6 more)
Current search
agents fundamentally lack the ability to simultaneously perform deep
reasoning over multi-hop
retrieval and wide-scale information collection-a critical deficiency for real-world applications like comprehensive
market analysis and business development. To bridge this gap, we introduce DeepWideSearch, the first
benchmark explicitly designed to evaluate
agents to integrate depth and width in information seeking. In DeepWideSearch,
agents must process a large volume of data, each requiring deep
reasoning over multi-hop
retrieval paths. Specifically, we propose two methods to converse established
datasets, resulting in a curated collection of 220 questions spanning 15 diverse domains. Extensive experiments demonstrate that even state-of-the-art
agents achieve only 2.39% average success rate on DeepWideSearch, highlighting the substantial challenge of integrating depth and width search in information-seeking tasks. Furthermore, our error analysis reveals four failure modes: lack of reflection, overreliance on internal knowledge, insufficient
retrieval, and context overflow-exposing key limitations in current
agent architectures. We publicly release DeepWideSearch to catalyze future research on more capable and robust information-seeking
agents.
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All authors Tian Lan, Bin Zhu, Qianghuai Jia, Junyang Ren, Haijun Li, Longyue Wang, Zhao Xu, Weihua Luo, Kaifu Zhang
Computation and Language
Are Stereotypes Leading LLMs' Zero-Shot Stance Detection ?
Anthony Dubreuil, Antoine Gourru, Christine Largeron et al. (+1 more)
Large
Language Models inherit stereotypes from their pretraining data, leading to biased behavior toward certain social groups in many Natural
Language Processing tasks, such as hateful
speech detection or sentiment analysis. Surprisingly, the evaluation of this kind of bias in stance detection methods has been largely overlooked by the community. Stance Detection involves labeling a statement as being against, in favor, or neutral towards a specific target and is among the most sensitive NLP tasks, as it often relates to political leanings. In this paper, we focus on the bias of Large
Language Models when performing stance detection in a zero-shot setting. We automatically annotate posts in pre-existing stance detection
datasets with two attributes: dialect or vernacular of a specific group and text complexity/readability, to investigate whether these attributes influence the model's stance detection decisions. Our results show that LLMs exhibit significant stereotypes in stance detection tasks, such as incorrectly associating pro-marijuana views with low text complexity and African American dialect with opposition to Donald Trump.
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All authors Anthony Dubreuil, Antoine Gourru, Christine Largeron, Amine Trabelsi
Computation and Language
BoundRL: Efficient Structured Text Segmentation through Reinforced Boundary Generation
Haoyuan Li, Zhengyuan Shen, Sullam Jeoung et al. (+6 more)
Structured texts refer to texts containing structured elements beyond plain texts, such as code snippets and placeholders. Such structured texts increasingly require
segmentation into semantically meaningful components, which cannot be effectively handled by conventional sentence-level
segmentation methods. To address this, we propose BoundRL, a novel approach that jointly performs efficient
token-level text
segmentation and label prediction for long structured texts. Instead of generating full texts for each segment, it generates only starting
tokens and reconstructs the complete texts by locating these
tokens within the original texts, thereby reducing output
tokens by 90% and minimizing
hallucination. To train the models for the boundary generation, BoundRL~performs reinforcement learning with verifiable rewards (RLVR) that jointly optimizes document reconstruction fidelity and semantic
alignment. It further mitigates
entropy collapse by constructing intermediate candidates by perturbing segment boundaries and labels to create stepping stones toward higher-quality solutions. Experiments show that BoundRL enables small
language models (1.7B parameters) to outperform few-shot prompting with much larger models as well as SFT and standard RLVR baselines on complex
prompts used for LLM applications.
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All authors Haoyuan Li, Zhengyuan Shen, Sullam Jeoung, Yueyan Chen, Jiayu Li, Qi Zhu, Shuai Wang, Vassilis Ioannidis, Huzefa Rangwala
Computation and Language · Cross-listed from cs.AI
AI PB: A Grounded Generative Agent for Personalized Investment Insights
Daewoo Park, Suho Park, Inseok Hong et al. (+5 more)
We present AI PB, a production-scale generative
agent deployed in real retail finance. Unlike reactive chatbots that answer queries passively, AI PB proactively generates grounded, compliant, and user-specific investment insights. It integrates (i) a component-based orchestration layer that deterministically routes between internal and external LLMs based on data sensitivity, (ii) a hybrid
retrieval pipeline using OpenSearch and the finance-domain
embedding model, and (iii) a multi-stage recommendation mechanism combining rule heuristics, sequential behavioral modeling, and contextual bandits. Operating fully on-premises under Korean financial regulations, the system employs Docker Swarm and vLLM across 24 X NVIDIA H100 GPUs. Through human QA and system metrics, we demonstrate that grounded generation with explicit routing and layered safety can deliver trustworthy AI insights in high-stakes finance.
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All authors Daewoo Park, Suho Park, Inseok Hong, Hanwool Lee, Junkyu Park, Sangjun Lee, Jeongman An, Hyunbin Loh
Computation and Language
Leveraging the Power of Large Language Models in Entity Linking via Adaptive Routing and Targeted Reasoning
Yajie Li, Albert Galimov, Mitra Datta Ganapaneni et al. (+4 more)
Entity Linking (EL) has traditionally relied on large annotated
datasets and extensive model fine-tuning. While recent few-shot methods leverage large
language models (LLMs) through prompting to reduce training requirements, they often suffer from inefficiencies due to expensive LLM-based
reasoning. ARTER (Adaptive Routing and Targeted Entity
Reasoning) presents a structured pipeline that achieves high performance without deep fine-tuning by strategically combining candidate generation, context-based scoring, adaptive routing, and selective
reasoning. ARTER computes a small set of complementary signals(both
embedding and LLM-based) over the retrieved candidates to categorize contextual mentions into easy and hard cases. The cases are then handled by a low-computational entity linker (e.g. ReFinED) and more expensive targeted LLM-based
reasoning respectively. On standard
benchmarks, ARTER outperforms ReFinED by up to +4.47%, with an average gain of +2.53% on 5 out of 6
datasets, and performs comparably to pipelines using LLM-based
reasoning for all mentions, while being as twice as efficient in terms of the number of LLM
tokens.
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All authors Yajie Li, Albert Galimov, Mitra Datta Ganapaneni, Pujitha Thejaswi, De Meng, Priyanshu Kumar, Saloni Potdar
Computation and Language · Cross-listed from cs.CV
BioCAP: Exploiting Synthetic Captions Beyond Labels in Biological Foundation Models
Ziheng Zhang, Xinyue Ma, Arpita Chowdhury et al. (+9 more)
This work investigates descriptive captions as an additional source of supervision for biological
multimodal foundation models. Images and captions can be viewed as complementary samples from the latent morphospace of a species, each capturing certain biological traits. Incorporating captions during training encourages
alignment with this shared latent structure, emphasizing potentially diagnostic characters while suppressing spurious correlations. The main challenge, however, lies in obtaining faithful, instance-specific captions at scale. This requirement has limited the utilization of natural
language supervision in organismal biology compared with many other scientific domains. We complement this gap by generating synthetic captions with
multimodal large
language models (MLLMs), guided by Wikipedia-derived visual information and taxon-tailored format examples. These domain-specific contexts help reduce
hallucination and yield accurate, instance-based descriptive captions. Using these captions, we train BioCAP (i.e., BioCLIP with Captions), a biological foundation model that captures rich semantics and achieves strong performance in species classification and text-image
retrieval. These results demonstrate the value of descriptive captions beyond labels in bridging biological images with
multimodal foundation models.
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All authors Ziheng Zhang, Xinyue Ma, Arpita Chowdhury, Elizabeth G. Campolongo, Matthew J. Thompson, Net Zhang, Samuel Stevens, Hilmar Lapp, Tanya Berger-Wolf, Yu Su, Wei-Lun Chao, Jianyang Gu
Computation and Language
CreativityPrism: A Cross-Domain Evaluation Framework for Large Language Model Creativity
Zhaoyi Joey Hou, Bowei Alvin Zhang, Yining Lu et al. (+9 more)
Creativity is often seen as a hallmark of human intelligence. While large
language models(LLMs) are increasingly perceived as generating creative text, there is still no cross-domain and scalable framework to evaluate their creativity across diverse scenarios. Existing methods of LLM creativity evaluation either heavily rely on humans, limiting speed and scalability, or are fragmented across different domains and different definitions of creativity. To address this gap, we propose CreativityPrism, an evaluation and analysis framework that consolidates eight tasks from three domains: divergent thinking, creative writing, and logical
reasoning, into a taxonomy of creativity that emphasizes three dimensions: quality, novelty, and diversity of LLM generations. The framework is designed to be scalable with reliable automatic evaluation judges that have been validated against human annotations. We evaluate 17 state-of-the-art (SoTA) LLMs on CreativityPrism and find that while frontier-scale LLMs dominate creative writing and logical
reasoning tasks by a .10 (or 15%) lead over locally-deployable open models, they offer no significant advantage in divergent thinking, a domain much less explored in existing post-training regimes. Our analysis also shows that high performance in one creative dimension or domain rarely generalizes to others; specifically, novelty metrics often show weak or negative correlations with other metrics. This fragmentation confirms that a cross-domain, multi-dimensional framework like CreativityPrism is essential for any meaningful assessment of LLM creativity.
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All authors Zhaoyi Joey Hou, Bowei Alvin Zhang, Yining Lu, Bhiman Kumar Baghel, Anneliese Brei, Ximing Lu, Meng Jiang, Faeze Brahman, Snigdha Chaturvedi, Haw-Shiuan Chang, Daniel Khashabi, Xiang Lorraine Li