Wei Xu
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2026
CoCoA: Context-Conditional Cultural Alignment for Large Language Models
Kyungdon Lee | Wei Xu | Alan Ritter | Dong-Ho Lee | JinYeong Bak
Findings of the Association for Computational Linguistics: EMNLP 2026
Kyungdon Lee | Wei Xu | Alan Ritter | Dong-Ho Lee | JinYeong Bak
Findings of the Association for Computational Linguistics: EMNLP 2026
Large Language Models (LLMs) often favor Western-associated entities across cultural contexts. Conventional debiasing methods aim for uniform neutrality, but cultural bias mitigation demands context-conditional behavior, preferring culturally appropriate entities when cultural cues are present and remaining neutral when they are absent. We propose CoCoA (Context-Conditional Cultural Alignment), a framework that learns this behavior through dual-context training on the same entity pairs under contexts with and without cultural cues. CoCoA combines a contrastive alignment objective with calibration and drift regularization, optimized through goal-aware gradient reconciliation. We evaluate CoCoA on CAMeL and Camellia, two entity-centric cultural bias benchmarks, across ten language settings and four LLMs. CoCoA reduces the Cultural Bias Score from 43 to 24 on average while maintaining near-neutral preferences at 50.2, with minimal impact on general performance across five standard benchmarks. These findings highlight that effective cultural alignment requires context-conditional modeling rather than uniform debiasing, and establish a new direction for mitigating entity-centric cultural bias in LLMs.
Localizing Prompt Ambiguity in Large Language Models with Probe-Targeted Attribution
Govind Ramesh | Yao Dou | Wei Xu
Findings of the Association for Computational Linguistics: EMNLP 2026
Govind Ramesh | Yao Dou | Wei Xu
Findings of the Association for Computational Linguistics: EMNLP 2026
Prompt ambiguity is a common source of failure in large language models, but is difficult to localize because it is a latent property of the prompt, while existing attribution methods are designed to explain observable outputs such as logits or generated tokens. We introduce PRIG, a gradient attribution method that uses a probe logit to attribute latent properties to token positions. Specifically, PRIG trains a linear probe to distinguish clear prompts from ambiguous prompts and attributes the probe score to earlier token representations in the residual stream. To enable token-level evaluation, we construct synthetic ambiguity datasets across coding, math, and writing by rewriting one task-critical sentence per prompt, and complement them with a human-written gold benchmark. In this setting, PRIG localizes ambiguous spans substantially better than gradient attribution baselines, achieving 0.840 AUROC on the combined synthetic benchmark. It also outperforms GPT-5.4 on sentence-level ambiguity identification and retains useful signal out-of-domain. More broadly, these results show that latent prompt properties can be localized through intermediate representations, rather than through output-level attribution.
VakyArth: Evaluating Pragmatic Competence in LLMs across Indic Languages
Usneek Singh | Poorvaja Veera Balaji Kumar | Parth Nanda | Anand Madhusoodanan | Geyang Guo | Wei Xu | Junyi Jessy Li
Findings of the Association for Computational Linguistics: EMNLP 2026
Usneek Singh | Poorvaja Veera Balaji Kumar | Parth Nanda | Anand Madhusoodanan | Geyang Guo | Wei Xu | Junyi Jessy Li
Findings of the Association for Computational Linguistics: EMNLP 2026
Real-world communication often requires pragmatic reasoning: interpreting meanings implied through context and cultural convention rather than stated literally. Existing pragmatic evaluation remains largely limited to English and high-resource languages, leaving Indic languages unexplored despite their linguistic and cultural diversity. We introduce VakyArth, the first pragmatic benchmark for Indic languages, designed as a diagnostic evaluation covering Hindi, Punjabi, Tamil, and Malayalam. VakyArth evaluates models across five phenomena: deixis, speech acts, implicature, social pragmatics, and coherence; through multiple-choice questions, natural language inference, and translation, with all items authored by native speakers. Across multilingual large language models (LLMs) of varying families and sizes, we find consistent failures on pragmatic meanings rooted in Indic linguistic and cultural conventions. Our analysis shows systematic differences across languages and tasks: MCQ accuracy exceeds NLI accuracy in all model-language combinations, translation performance does not reliably track pragmatic understanding, and Indo-Aryan languages show a translation advantage over Dravidian languages. We further show that automatic translation metrics can miss fluent but pragmatically unfaithful outputs, especially for implicature and deixis.
Faithfulness vs. Safety: Evaluating LLM Behavior Under Counterfactual Medical Evidence
Kaijie Mo | Siddhartha Venkatayogi | Chantal Shaib | Ramez Kouzy | Wei Xu | Byron C Wallace | Junyi Jessy Li
Findings of the Association for Computational Linguistics: ACL 2026
Kaijie Mo | Siddhartha Venkatayogi | Chantal Shaib | Ramez Kouzy | Wei Xu | Byron C Wallace | Junyi Jessy Li
Findings of the Association for Computational Linguistics: ACL 2026
In high-stakes domains like medicine, it may be generally desirable for models to faithfully adhere to the context provided. But what happens if the context does not align with model priors or safety protocols? In this paper, we investigate how LLMs behave and reason when presented with counterfactual (or even adversarial) medical evidence. We first construct MedCounterFact, a counterfactual medical QA dataset that requires the models to answer clinical comparison questions (i.e., judge the efficacy of certain treatments, with evidence consisting of randomized controlled trials provided as context). In MedCounterFact, real-world medical interventions within the questions and evidence are systematically replaced with four types of counterfactual stimuli, ranging from unknown words to toxic substances. Our evaluation across multiple frontier LLMs on MedCounterFact reveals that in the presence of counterfactual evidence, existing models overwhelmingly accept such “evidence” at face value even when it is dangerous or implausible, and provide confident and uncaveated answers. While it may be prudent to draw a boundary between faithfulness and safety, our findings suggest that models arguably overemphasize the former.
Multilingual and Multicultural LLMs
Wei Xu | David Ifeoluwa Adelani | Vinodkumar Prabhakaran | Sara Hooker | Alan Ritter
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Tutorial Abstracts
Wei Xu | David Ifeoluwa Adelani | Vinodkumar Prabhakaran | Sara Hooker | Alan Ritter
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Tutorial Abstracts
While large language models (LLMs) have substantially expanded support for non-English languages, their ability to generalize across typologically diverse languages and produce contextually appropriate, culturally grounded responses remains a significant challenge. This tutorial examines the rapidly evolving area of understanding, evaluating, and improving the multilingual capabilities and multicultural alignment of LLMs. We will primarily focus on cutting-edge advances and latest publications from 2025–2026, while incorporating selected introductory material to provide necessary background and to ensure accessibility for a broad audience. Participants will gain an up-to-date view of both methods and practical insights, including multilingual pre-, mid- and post-training, multilingual-specific optimization techniques, culturally aware evaluation, and key open problems in developing more fair, inclusive, and robust LLMs.
Camellia: Benchmarking Cultural Biases in LLMs for Asian Languages
Tarek Naous | Anagha Savit | Carlos Rafael Catalan | Geyang Guo | Jaehyeok Lee | Kyungdon Lee | Lheane Marie Dizon | Mengyu Ye | Neel Kothari | Sahajpreet Singh | Sarah Masud | Tanish Patwa | Trung Thanh Tran | Zohaib Khan | Alan Ritter | Tanmoy Chakraborty | Yuki Arase | Keisuke Sakaguchi | JinYeong Bak | Wei Xu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Tarek Naous | Anagha Savit | Carlos Rafael Catalan | Geyang Guo | Jaehyeok Lee | Kyungdon Lee | Lheane Marie Dizon | Mengyu Ye | Neel Kothari | Sahajpreet Singh | Sarah Masud | Tanish Patwa | Trung Thanh Tran | Zohaib Khan | Alan Ritter | Tanmoy Chakraborty | Yuki Arase | Keisuke Sakaguchi | JinYeong Bak | Wei Xu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
As Large Language Models (LLMs) develop stronger multilingual capabilities, their sensitivity to culturally diverse entities becomes increasingly important. Prior work by Naous et al. (2024) has shown that LLMs often favor Western-associated entities in Arabic. Due to the lack of entity-centric multilingual benchmarks, it remains unclear if such biases also manifest in various non-Western languages. In this paper, we introduce Camellia, a benchmark for evaluating entity-centric cultural biases in nine Asian languages, spanning six Asian cultures. Camellia includes 19,530 manually annotated entities associated with the covered Asian or Western cultures, as well as 2,173 masked contexts for these entities derived from social media posts. Using Camellia, we evaluate cultural biases in four recent multilingual LLMs across three tasks: cultural context adaptation, sentiment association, and entity extractive QA. Our analyses show that LLMs struggle with cultural adaptation across these languages, with performance differing across models developed in different regions. We further observe that different LLM families can hold distinct biases, reflected in the ways they link cultures to particular sentiments. Lastly, we find that LLMs can struggle with context understanding in some Asian languages, creating performance gaps between cultures in entity extraction.
Gavel: Agent Meets Checklist for Evaluating LLMs on Long-Context Legal Summarization
Yao Dou | Benjamin Mamut | Wei Xu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Yao Dou | Benjamin Mamut | Wei Xu
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) now support contexts of up to 1M tokens, but their strengths and weaknesses on complex long-context tasks remain unclear. To study this, we focus on multi-document legal case summarization, where a single case often spans many documents exceeding 100K tokens. We systematically evaluate 12 frontier LLMs with Gavel, which consists of Gavel-Ref, a reference-based evaluation framework with checklist, residual-fact, and writing-style evaluations, and Gavel-Agent, a reference-free agent for evaluating factual coverage directly from source documents. Our results show that current models are more prone to omitting key information than hallucinating. They all perform well on simple checklist items, such as filing date, but struggle with rare and complex items, such as settlements. Performance also declines as case length increases. To meta-evaluate Gavel, we collect 160 hours of human annotations. Gavel-Agent reduces token usage by at least 36% compared to end-to-end and chunk-by-chunk methods while achieving competitive performance. Gavel-Agent also generalizes to the medical domain, achieving the best performance with at least 77% fewer tokens. We will release our code and annotations publicly.
Investigating and Alleviating Harm Amplification in LLM Interactions
Ruohao Guo | Wei Xu | Alan Ritter
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Ruohao Guo | Wei Xu | Alan Ritter
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) can serve as helpful assistants, yet they can equally function as harm amplifiers that enable malicious users to achieve harmful outcomes beyond their capabilities through extended interactions. This risk manifests along two axes, i.e., democratizing domain expertise that allows novices to produce specialized harmful content, and scaling harmful operations at volumes that manual effort cannot match. Existing works, however, often overlook how LLMs compound harm across multi-turn conversations. We introduce HarmAmp, a new benchmark for multi-turn harm amplification scenarios spanning twelve risk categories. Each scenario is grounded in real-world threats and satisfies rigorous criteria, i.e., substantive amplification, operational specificity, and multi-turn necessity. We further propose TrajSafe, a proactive monitor that anticipates harmful trajectories and intervenes through actions such as probing users’ genuine intents and steering the models towards safer completion. Our extensive experiments demonstrate that TrajSafe significantly reduces the harmfulness incurred in multi-turn interactions while preserving a low over-refusal rate and the target model’s general capabilities. Our work offers a promising paradigm to alleviate the nuanced safety risks in LLM interactions.
GeoRC: A Benchmark for Geolocation Reasoning Chains
Mohit Talreja | Joshua Diao | Jim James | Radu Casapu | Tejas Santanam | Ethan Mendes | Alan Ritter | Wei Xu | James Hays
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Mohit Talreja | Joshua Diao | Jim James | Radu Casapu | Tejas Santanam | Ethan Mendes | Alan Ritter | Wei Xu | James Hays
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Vision Language Models (VLMs) are good at recognizing the global location of a photograph – their geolocation prediction accuracy rivals the best human experts. But many VLMs are startlingly bad at explaining which image evidence led to their prediction, even when their location prediction is correct. The reasoning chains produced by VLMs frequently hallucinate scene attributes to support their location prediction (e.g. phantom writing, imagined infrastructure, misidentified flora). In this paper, we introduce the first benchmark for geolocation reasoning chains. We focus on the global location prediction task in the popular GeoGuessr game which draws from Google Street View spanning more than 100 countries. We collaborate with expert GeoGuessr players, including the reigning world champion, to produce 800 “ground truth” reasoning chains for 500 query scenes. These expert reasoning chains address hundreds of different discriminative visual attributes such as license plate shape, architecture, and soil properties to name just a few. We evaluate LLM-as-a-judge and VLM-as-a-judge strategies for scoring VLM-generated reasoning chains against our expert reasoning chains and find that Qwen 3 LLM-as-a-judge correlates best with human scoring. Our benchmark reveals that while large, closed-source VLMs such as Gemini and GPT 5 rival human experts at prediction locations, they still lag behind human experts when it comes to producing auditable reasoning chains. Open weights VLMs such as Llama and Qwen catastrophically fail on our benchmark – they perform only slightly better than a baseline in which an LLM hallucinates a reasoning chain with oracle knowledge of the photo location but no visual information at all. We believe the gap between human experts and VLMs on this task points to VLM limitations at extracting fine-grained visual attributes from high resolution images. We open source our benchmark for the community to use.
2025
BiasEdit: Debiasing Stereotyped Language Models via Model Editing
Xin Xu | Wei Xu | Ningyu Zhang | Julian McAuley
Proceedings of the 5th Workshop on Trustworthy NLP (TrustNLP 2025)
Xin Xu | Wei Xu | Ningyu Zhang | Julian McAuley
Proceedings of the 5th Workshop on Trustworthy NLP (TrustNLP 2025)
Previous studies have established that language models manifest stereotyped biases. Existing debiasing strategies, such as retraining a model with counterfactual data, representation projection, and prompting often fail to efficiently eliminate bias or directly alter the models’ biased internal representations. To address these issues, we propose BiasEdit, an efficient model editing method to remove stereotypical bias from language models through lightweight networks that act as editors to generate parameter updates. BiasEdit employs a debiasing loss guiding editor networks to conduct local edits on partial parameters of a language model for debiasing while preserving the language modeling abilities during editing through a retention loss. Experiments on StereoSet and Crows-Pairs demonstrate the effectiveness, efficiency, and robustness of BiasEdit in eliminating bias compared to tangental debiasing baselines, and little to no impact on the language models’ general capabilities. In addition, we conduct bias tracing to probe bias in various modules and explore bias editing impacts on different components of language models.
On The Origin of Cultural Biases in Language Models: From Pre-training Data to Linguistic Phenomena
Tarek Naous | Wei Xu
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Tarek Naous | Wei Xu
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Language Models (LMs) have been shown to exhibit a strong preference towards entities associated with Western culture when operating in non-Western languages. In this paper, we aim to uncover the origins of entity-related cultural biases in LMs by analyzing several contributing factors, including the representation of entities in pre-training data and the impact of variations in linguistic phenomena across languages. We introduce CAMeL-2, a parallel Arabic-English benchmark of 58,086 entities associated with Arab and Western cultures and 367 masked natural contexts for entities. Our evaluations using CAMeL-2 reveal reduced performance gaps between cultures by LMs when tested in English compared to Arabic. We find that LMs struggle in Arabic with entities that appear at high frequencies in pre-training, where entities can hold multiple word senses. This also extends to entities that exhibit high lexical overlap with languages that are not Arabic but use the Arabic script. Further, we show how frequency-based tokenization leads to this issue in LMs, which gets worse with larger Arabic vocabularies. We will make CAMeL-2 available at: https://github.com/tareknaous/camel2
The Impact of Visual Information in Chinese Characters: Evaluating Large Models’ Ability to Recognize and Utilize Radicals
Xiaofeng Wu | Karl Stratos | Wei Xu
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Xiaofeng Wu | Karl Stratos | Wei Xu
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
The glyphic writing system of Chinese incorporates information-rich visual features in each character, such as radicals that provide hints about meaning or pronunciation. However, there has been no investigation into whether contemporary Large Language Models (LLMs) and Vision-Language Models (VLMs) can harness these sub-character features in Chinese through prompting. In this study, we establish a benchmark to evaluate LLMs’ and VLMs’ understanding of visual elements in Chinese characters, including radicals, composition structures, strokes, and stroke counts. Our results reveal that models surprisingly exhibit some, but still limited, knowledge of the visual information, regardless of whether images of characters are provided. To incite models’ ability to use radicals, we further experiment with incorporating radicals into the prompts for Chinese language processing (CLP) tasks. We observe consistent improvement in Part-Of-Speech tagging when providing additional information about radicals, suggesting the potential to enhance CLP by integrating sub-character information.
SimulatorArena: Are User Simulators Reliable Proxies for Multi-Turn Evaluation of AI Assistants?
Yao Dou | Michel Galley | Baolin Peng | Chris Kedzie | Weixin Cai | Alan Ritter | Chris Quirk | Wei Xu | Jianfeng Gao
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Yao Dou | Michel Galley | Baolin Peng | Chris Kedzie | Weixin Cai | Alan Ritter | Chris Quirk | Wei Xu | Jianfeng Gao
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) are increasingly used in interactive applications, and human evaluation remains the gold standard for assessing their performance in multi-turn conversations. Since human studies are costly, time-consuming, and hard to reproduce, recent work explores using LLMs to simulate users for automatic assistant evaluation. However, there is no benchmark or systematic study to evaluate whether these simulated users are reliable stand-ins for real users. To address this, we introduce SimulatorArena, a benchmark of 909 annotated human–LLM conversations on two interactive tasks—math tutoring and document creation. SimulatorArena evaluates simulators based on how closely their messages match human behavior and how well their assistant ratings align with human judgments. Experiments on various simulator methods show that simulators conditioned on user profiles, capturing traits like background and message styles, align closely with human judgments. They reach Spearman’s 𝜌 of 0.7 on both tasks, providing a practical, scalable alternative to human evaluation. Using the best simulator for each task, we benchmark 18 assistants, including the latest LLMs such as GPT-5, Claude 4.1 Opus, and Gemini 2.5 Pro.
CARE: Multilingual Human Preference Learning for Cultural Awareness
Geyang Guo | Tarek Naous | Hiromi Wakaki | Yukiko Nishimura | Yuki Mitsufuji | Alan Ritter | Wei Xu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Geyang Guo | Tarek Naous | Hiromi Wakaki | Yukiko Nishimura | Yuki Mitsufuji | Alan Ritter | Wei Xu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Language Models (LMs) are typically tuned with human preferences to produce helpful responses, but the impact of preference tuning on the ability to handle culturally diverse queries remains understudied. In this paper, we systematically analyze how native human cultural preferences can be incorporated into the preference learning process to train more culturally aware LMs. We introduce CARE, a multilingual resource containing 3,490 culturally specific questions and 31.7k responses with human judgments. We demonstrate how a modest amount of high-quality native preferences improves cultural awareness across various LMs, outperforming larger generic preference data. Our analyses reveal that models with stronger initial cultural performance benefit more from alignment, leading to gaps among models developed in different regions with varying access to culturally relevant data. CARE is publicly available at https://github.com/Guochry/CARE.
How to Protect Yourself from 5G Radiation? Investigating LLM Responses to Implicit Misinformation
Ruohao Guo | Wei Xu | Alan Ritter
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Ruohao Guo | Wei Xu | Alan Ritter
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
As Large Language Models (LLMs) are widely deployed in diverse scenarios, the extent to which they could tacitly spread misinformation emerges as a critical safety concern. Current research primarily evaluates LLMs on explicit false statements, overlooking how misinformation often manifests subtly as unchallenged premises in real-world interactions. We curated EchoMist, the first comprehensive benchmark for implicit misinformation, where false assumptions are embedded in the query to LLMs. EchoMist targets circulated, harmful, and ever-evolving implicit misinformation from diverse sources, including realistic human-AI conversations and social media interactions. Through extensive empirical studies on 15 state-of-the-art LLMs, we find that current models perform alarmingly poorly on this task, often failing to detect false premises and generating counterfactual explanations. We also investigate two mitigation methods, i.e., Self-Alert and RAG, to enhance LLMs’ capability to counter implicit misinformation. Our findings indicate that EchoMist remains a persistent challenge and underscore the critical need to safeguard against the risk of implicit misinformation.
What are Foundation Models Cooking in the Post-Soviet World?
Anton Lavrouk | Tarek Naous | Alan Ritter | Wei Xu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Anton Lavrouk | Tarek Naous | Alan Ritter | Wei Xu
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
The culture of the Post-Soviet states is complex, shaped by a turbulent history that continues to influence current events. In this study, we investigate the Post-Soviet cultural food knowledge of foundation models by constructing BORSch, a multi-modal dataset encompassing 1147 and 823 dishes in the Russian and Ukrainian languages, centered around the Post-Soviet region. We demonstrate that leading models struggle to correctly identify the origins of dishes from Post-Soviet nations in both text-only and multi-modal Question Answering (QA), instead over-predicting countries linked to the language the question is asked in. Through analysis of pre-training data, we show that these results can be explained by misleading dish-origin co-occurrences, along with linguistic phenomena such as Russian-Ukrainian code mixing. Finally, to move beyond QA-based assessments, we test models’ abilities to produce accurate visual descriptions of dishes. The weak correlation between this task and QA suggests that QA alone may be insufficient as an evaluation of cultural understanding.
2024
Stanceosaurus 2.0 - Classifying Stance Towards Russian and Spanish Misinformation
Anton Lavrouk | Ian Ligon | Jonathan Zheng | Tarek Naous | Wei Xu | Alan Ritter
Proceedings of the Ninth Workshop on Noisy and User-generated Text (W-NUT 2024)
Anton Lavrouk | Ian Ligon | Jonathan Zheng | Tarek Naous | Wei Xu | Alan Ritter
Proceedings of the Ninth Workshop on Noisy and User-generated Text (W-NUT 2024)
The Stanceosaurus corpus (Zheng et al., 2022) was designed to provide high-quality, annotated, 5-way stance data extracted from Twitter, suitable for analyzing cross-cultural and cross-lingual misinformation. In the Stanceosaurus 2.0 iteration, we extend this framework to encompass Russian and Spanish. The former is of current significance due to prevalent misinformation amid escalating tensions with the West and the violent incursion into Ukraine. The latter, meanwhile, represents an enormous community that has been largely overlooked on major social media platforms. By incorporating an additional 3,874 Spanish and Russian tweets over 41 misinformation claims, our objective is to support research focused on these issues. To demonstrate the value of this data, we employed zero-shot cross-lingual transfer on multilingual BERT, yielding results on par with the initial Stanceosaurus study with a macro F1 score of 43 for both languages. This underlines the viability of stance classification as an effective tool for identifying multicultural misinformation.
MedReadMe: A Systematic Study for Fine-grained Sentence Readability in Medical Domain
Chao Jiang | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Chao Jiang | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Medical texts are notoriously challenging to read. Properly measuring their readability is the first step towards making them more accessible. Here, we present the first systematic study on fine-grained readability measurements in the medical domain, at both sentence-level and span-level. We first introduce a new dataset MedReadMe, which consists of manually annotated readability ratings and fine-grained complex span annotation for 4,520 sentences, featuring two novel “Google-Easy” and “Google-Hard” categories. It supports our quantitative analysis, which covers 650 linguistic features and additional complex span features, to answer “why medical sentences are so hard.” Enabled by our high-quality annotation, we benchmark several state-of-the-art sentence-level readability metrics, including unsupervised, supervised, and prompting-based methods using recently developed large language models (LLMs). Informed by our fine-grained complex span annotation, we find that adding a single feature, capturing the number of jargon spans, into existing readability formulas can significantly improve their correlation with human judgments, and also make them more stable. We will publicly release data and code.
Granular Privacy Control for Geolocation with Vision Language Models
Ethan Mendes | Yang Chen | James Hays | Sauvik Das | Wei Xu | Alan Ritter
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Ethan Mendes | Yang Chen | James Hays | Sauvik Das | Wei Xu | Alan Ritter
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Vision Language Models (VLMs) are rapidly advancing in their capability to answer information-seeking questions. As these models are widely deployed in consumer applications, they could lead to new privacy risks due to emergent abilities to identify people in photos, geolocate images, etc. As we demonstrate, somewhat surprisingly, current open-source and proprietary VLMs are very capable image geolocators, making widespread geolocation with VLMs an immediate privacy risk, rather than merely a theoretical future concern. As a first step to address this challenge, we develop a new benchmark, GPTGeoChat, to test the capability of VLMs to moderate geolocation dialogues with users. We collect a set of 1,000 image geolocation conversations between in-house annotators and GPT-4v, which are annotated with the granularity of location information revealed at each turn. Using this new dataset we evaluate the ability of various VLMs to moderate GPT-4v geolocation conversations by determining when too much location information has been revealed. We find that custom fine-tuned models perform on par with prompted API-based models when identifying leaked location information at the country or city level, however fine-tuning on supervised data appears to be needed to accurately moderate finer granularities, such as the name of a restaurant or building.
ReadMe++: Benchmarking Multilingual Language Models for Multi-Domain Readability Assessment
Tarek Naous | Michael J Ryan | Anton Lavrouk | Mohit Chandra | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Tarek Naous | Michael J Ryan | Anton Lavrouk | Mohit Chandra | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
We present a comprehensive evaluation of large language models for multilingual readability assessment. Existing evaluation resources lack domain and language diversity, limiting the ability for cross-domain and cross-lingual analyses. This paper introduces ReadMe++, a multilingual multi-domain dataset with human annotations of 9757 sentences in Arabic, English, French, Hindi, and Russian, collected from 112 different data sources. This benchmark will encourage research on developing robust multilingual readability assessment methods. Using ReadMe++, we benchmark multilingual and monolingual language models in the supervised, unsupervised, and few-shot prompting settings. The domain and language diversity in ReadMe++ enable us to test more effective few-shot prompting, and identify shortcomings in state-of-the-art unsupervised methods. Our experiments also reveal exciting results of superior domain generalization and enhanced cross-lingual transfer capabilities by models trained on ReadMe++. We will make our data publicly available and release a python package tool for multilingual sentence readability prediction using our trained models at: https://github.com/tareknaous/readme
Improving Minimum Bayes Risk Decoding with Multi-Prompt
David Heineman | Yao Dou | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
David Heineman | Yao Dou | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
While instruction fine-tuned LLMs are effective text generators, sensitivity to prompt construction makes performance unstable and sub-optimal in practice. Relying on a single ‘best’ prompt cannot capture all differing approaches to a generation problem. Using this observation, we propose multi-prompt decoding, where many candidate generations are decoded from a prompt bank at inference-time. To ensemble candidates, we use Minimum Bayes Risk (MBR) decoding, which selects a final output using a trained value metric. We show multi-prompt improves MBR across a comprehensive set of conditional generation tasks, and show this is a result of estimating a more diverse and higher quality candidate space than that of a single prompt. Our experiments confirm multi-prompt improves generation across tasks, models and metrics.
GPT-4 Jailbreaks Itself with Near-Perfect Success Using Self-Explanation
Govind Ramesh | Yao Dou | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Govind Ramesh | Yao Dou | Wei Xu
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Research on jailbreaking has been valuable for testing and understanding the safety and security issues of large language models (LLMs). In this paper, we introduce Iterative Refinement Induced Self-Jailbreak (IRIS), a novel approach that leverages the reflective capabilities of LLMs for jailbreaking with only black-box access. Unlike previous methods, IRIS simplifies the jailbreaking process by using a single model as both the attacker and target. This method first iteratively refines adversarial prompts through self-explanation, which is crucial for ensuring that even well-aligned LLMs obey adversarial instructions. IRIS then rates and enhances the output given the refined prompt to increase its harmfulness. We find that IRIS achieves jailbreak success rates of 98% on GPT-4, 92% on GPT-4 Turbo, and 94% on Llama-3.1-70B in under 7 queries. It significantly outperforms prior approaches in automatic, black-box, and interpretable jailbreaking, while requiring substantially fewer queries, thereby establishing a new standard for interpretable jailbreaking methods.
ChatHF: Collecting Rich Human Feedback from Real-time Conversations
Andrew Li | Zhenduo Wang | Ethan Mendes | Duong Minh Le | Wei Xu | Alan Ritter
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing: System Demonstrations
Andrew Li | Zhenduo Wang | Ethan Mendes | Duong Minh Le | Wei Xu | Alan Ritter
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing: System Demonstrations
We introduce ChatHF, an interactive annotation framework for chatbot evaluation, which integrates configurable annotation within a chat interface. ChatHF can be flexibly configured to accommodate various chatbot evaluation tasks, for example detecting offensive content, identifying incorrect or misleading information in chatbot responses, and chatbot responses that might compromise privacy. It supports post-editing of chatbot outputs and supports visual inputs, in addition to an optional voice interface. ChatHF is suitable for collection and annotation of NLP datasets, and Human-Computer Interaction studies, as demonstrated in case studies on image geolocation and assisting older adults with daily activities. ChatHF is publicly accessible at https://chat-hf.com.
2023
Teaching the Pre-trained Model to Generate Simple Texts for Text Simplification
Renliang Sun | Wei Xu | Xiaojun Wan
Findings of the Association for Computational Linguistics: ACL 2023
Renliang Sun | Wei Xu | Xiaojun Wan
Findings of the Association for Computational Linguistics: ACL 2023
Randomly masking text spans in ordinary texts in the pre-training stage hardly allows models to acquire the ability to generate simple texts. It can hurt the performance of pre-trained models on text simplification tasks. In this paper, we propose a new continued pre-training strategy to teach the pre-trained model to generate simple texts. We continue pre-training BART, a representative model, to obtain SimpleBART. It consistently and significantly improves the results on lexical simplification, sentence simplification, and document-level simplification tasks over BART. At the end, we compare SimpleBART with several representative large language models (LLMs).
Frustratingly Easy Label Projection for Cross-lingual Transfer
Yang Chen | Chao Jiang | Alan Ritter | Wei Xu
Findings of the Association for Computational Linguistics: ACL 2023
Yang Chen | Chao Jiang | Alan Ritter | Wei Xu
Findings of the Association for Computational Linguistics: ACL 2023
Translating training data into many languages has emerged as a practical solution for improving cross-lingual transfer. For tasks that involve span-level annotations, such as information extraction or question answering, an additional label projection step is required to map annotated spans onto the translated texts. Recently, a few efforts have utilized a simple mark-then-translate method to jointly perform translation and projection by inserting special markers around the labeled spans in the original sentence. However, as far as we are aware, no empirical analysis has been conducted on how this approach compares to traditional annotation projection based on word alignment. In this paper, we present an extensive empirical study across 57 languages and three tasks (QA, NER, and Event Extraction) to evaluate the effectiveness and limitations of both methods, filling an important gap in the literature. Experimental results show that our optimized version of mark-then-translate, which we call EasyProject, is easily applied to many languages and works surprisingly well, outperforming the more complex word alignment-based methods. We analyze several key factors that affect the end-task performance, and show EasyProject works well because it can accurately preserve label span boundaries after translation. We will publicly release all our code and data.
LENS: A Learnable Evaluation Metric for Text Simplification
Mounica Maddela | Yao Dou | David Heineman | Wei Xu
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Mounica Maddela | Yao Dou | David Heineman | Wei Xu
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Training learnable metrics using modern language models has recently emerged as a promising method for the automatic evaluation of machine translation. However, existing human evaluation datasets for text simplification have limited annotations that are based on unitary or outdated models, making them unsuitable for this approach. To address these issues, we introduce the SimpEval corpus that contains: SimpEval_past, comprising 12K human ratings on 2.4K simplifications of 24 past systems, and SimpEval_2022, a challenging simplification benchmark consisting of over 1K human ratings of 360 simplifications including GPT-3.5 generated text. Training on SimpEval, we present LENS, a Learnable Evaluation Metric for Text Simplification. Extensive empirical results show that LENS correlates much better with human judgment than existing metrics, paving the way for future progress in the evaluation of text simplification. We also introduce Rank & Rate, a human evaluation framework that rates simplifications from several models in a list-wise manner using an interactive interface, which ensures both consistency and accuracy in the evaluation process and is used to create the SimpEval datasets.
Human-in-the-loop Evaluation for Early Misinformation Detection: A Case Study of COVID-19 Treatments
Ethan Mendes | Yang Chen | Wei Xu | Alan Ritter
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Ethan Mendes | Yang Chen | Wei Xu | Alan Ritter
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
We present a human-in-the-loop evaluation framework for fact-checking novel misinformation claims and identifying social media messages that support them. Our approach extracts check-worthy claims, which are aggregated and ranked for review. Stance classifiers are then used to identify tweets supporting novel misinformation claims, which are further reviewed to determine whether they violate relevant policies. To demonstrate the feasibility of our approach, we develop a baseline system based on modern NLP methods for human-in-the-loop fact-checking in the domain of COVID-19 treatments. We make our data and detailed annotation guidelines available to support the evaluation of human-in-the-loop systems that identify novel misinformation directly from raw user-generated content.
Distill or Annotate? Cost-Efficient Fine-Tuning of Compact Models
Junmo Kang | Wei Xu | Alan Ritter
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Junmo Kang | Wei Xu | Alan Ritter
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Fine-tuning large models is highly effective, however, inference can be expensive and produces carbon emissions. Knowledge distillation has been shown to be a practical solution to reduce inference costs, but the distillation process itself requires significant computational resources. Rather than buying or renting GPUs to fine-tune, then distill a large model, an NLP practitioner might instead choose to allocate the available budget to hire annotators and manually label additional fine-tuning data. In this paper, we investigate how to most efficiently use a fixed budget to build a compact model. Through extensive experiments on six diverse tasks, we show that distilling from T5-XXL (11B) to T5-Small (60M) is almost always a cost-efficient strategy compared to annotating more data to directly train a compact model (T5-Small). We further investigate how the optimal budget allocated towards computation varies across scenarios. We will make our code, datasets, annotation cost estimates, and baseline models available as a benchmark to support further work on cost-efficient training of compact models.
Improved Instruction Ordering in Recipe-Grounded Conversation
Duong Le | Ruohao Guo | Wei Xu | Alan Ritter
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Duong Le | Ruohao Guo | Wei Xu | Alan Ritter
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
In this paper, we study the task of instructional dialogue and focus on the cooking domain. Analyzing the generated output of the GPT-J model, we reveal that the primary challenge for a recipe-grounded dialog system is how to provide the instructions in the correct order. We hypothesize that this is due to the model’s lack of understanding of user intent and inability to track the instruction state (i.e., which step was last instructed). Therefore, we propose to explore two auxiliary subtasks, namely User Intent Detection and Instruction State Tracking, to support Response Generation with improved instruction grounding. Experimenting with our newly collected dataset, ChattyChef, shows that incorporating user intent and instruction state information helps the response generation model mitigate the incorrect order issue. Furthermore, to investigate whether ChatGPT has completely solved this task, we analyze its outputs and find that it also makes mistakes (10.7% of the responses), about half of which are out-of-order instructions. We will release ChattyChef to facilitate further research in this area at: https://github.com/octaviaguo/ChattyChef.
Revisiting non-English Text Simplification: A Unified Multilingual Benchmark
Michael J Ryan | Tarek Naous | Wei Xu
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Michael J Ryan | Tarek Naous | Wei Xu
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Recent advancements in high-quality, large-scale English resources have pushed the frontier of English Automatic Text Simplification (ATS) research. However, less work has been done on multilingual text simplification due to the lack of a diverse evaluation benchmark that covers complex-simple sentence pairs in many languages. This paper introduces the MultiSim benchmark, a collection of 27 resources in 12 distinct languages containing over 1.7 million complex-simple sentence pairs. This benchmark will encourage research in developing more effective multilingual text simplification models and evaluation metrics. Our experiments using MultiSim with pre-trained multilingual language models reveal exciting performance improvements from multilingual training in non-English settings. We observe strong performance from Russian in zero-shot cross-lingual transfer to low-resource languages. We further show that few-shot prompting with BLOOM-176b achieves comparable quality to reference simplifications outperforming fine-tuned models in most languages. We validate these findings through human evaluation.
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- Alan Ritter 16
- Tarek Naous 7
- Yao Dou 6
- Ethan Mendes 4
- Yang Chen 3
- Geyang Guo 3
- Ruohao Guo 3
- Anton Lavrouk 3
- JinYeong Bak 2
- James Hays 2
- David Heineman 2
- Chao Jiang 2
- Kyungdon Lee 2
- Junyi Jessy Li 2
- Govind Ramesh 2
- Michael J. Ryan 2
- David Ifeoluwa Adelani 1
- Yuki Arase 1
- Weixin Cai 1
- Radu Casapu 1
- Carlos Rafael Catalan 1
- Tanmoy Chakraborty 1
- Mohit Chandra 1
- Sauvik Das 1
- Joshua Diao 1
- Lheane Marie Dizon 1
- Michel Galley 1
- Jianfeng Gao 1
- Sara Hooker 1
- Jim James 1
- Junmo Kang 1
- Chris Kedzie 1
- Zohaib Khan 1
- Neel Kothari 1
- Ramez Kouzy 1
- Poorvaja Veera Balaji Kumar 1
- Duong Le 1
- Duong Minh Le 1
- Dong-Ho Lee 1
- Jaehyeok Lee 1
- Andrew Li 1
- Ian Ligon 1
- Mounica Maddela 1
- Anand Madhusoodanan 1
- Benjamin Mamut 1
- Sarah Masud 1
- Julian McAuley 1
- Yuki Mitsufuji 1
- Kaijie Mo 1
- Parth Nanda 1
- Yukiko Nishimura 1
- Tanish Patwa 1
- Baolin Peng 1
- Vinodkumar Prabhakaran 1
- Chris Quirk 1
- Keisuke Sakaguchi 1
- Tejas Santanam 1
- Anagha Savit 1
- Chantal Shaib 1
- Sahajpreet Singh 1
- Usneek Singh 1
- Karl Stratos 1
- Renliang Sun 1
- Mohit Talreja 1
- Trung Thanh Tran 1
- Siddhartha Venkatayogi 1
- Hiromi Wakaki 1
- Byron C Wallace 1
- Xiaojun Wan 1
- Zhenduo Wang 1
- Xiaofeng Wu 1
- Xin Xu 1
- Mengyu Ye 1
- Ningyu Zhang 1
- Jonathan Zheng 1