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Bill Yuchen Lin

46 accepted papers

2026

ASCIIEval: Benchmarking Models' Visual Perception in Text Strings via ASCII Art

ICLR 2026poster

Perceiving visual semantics embedded within consecutive characters is a crucial yet under-explored capability for both Large Language Models (LLMs) and Multi-modal Large Language Models (MLLMs). In this work, we select ASCII art as a representative artifact. It depicts concepts through careful arran…

Cited by 0SourcecodeScholar
2025

ChatBug: A Common Vulnerability of Aligned LLMs Induced by Chat Templates

AAAI 2025technical

Large language models (LLMs) are expected to follow instructions from users and engage in conversations. Techniques to enhance LLMs' instruction-following capabilities typically fine-tune them using data structured according to a predefined chat template. Although chat templates are shown to be eff…

2025

CulturalBench: A Robust, Diverse and Challenging Benchmark for Measuring LMs’ Cultural Knowledge Through Human-AI Red-Teaming

ACL 2025long

Robust, diverse, and challenging cultural knowledge benchmarks are essential for measuring our progress towards making LMs that are helpful across diverse cultures. We introduce CulturalBench: a set of 1,696 human-written and human-verified questions to assess LMs’ cultural knowledge, covering 45 gl…

Cited by 0SourcePDFScholar
2025

Information-Guided Identification of Training Data Imprint in (Proprietary) Large Language Models

NAACL 2025long

High-quality training data has proven crucial for developing performant large language models (LLMs). However, commercial LLM providers disclose few, if any, details about the data used for training. This lack of transparency creates multiple challenges: it limits external oversight and inspection o…

Cited by 1SourcePDFScholar
2025

L3GO: Language Agents with Chain-of-3D-Thoughts for Generating Unconventional Objects

NAACL 2025system demonstrations

Diffusion-based image generation models such as DALL-E 3 and Stable Diffusion-XL demonstrate remarkable capabilities in generating images with realistic and unique compositions. Yet, these models are not robust in precisely reasoning about physical and spatial configurations of objects, especially w…

2025

Latent Action Pretraining from Videos

ICLR 2025poster

We introduce Latent Action Pretraining for general Action models (LAPA), the first unsupervised method for pretraining Vision-Language-Action (VLA) models without ground-truth robot action labels. Existing Vision-Language-Action models require action labels typically collected by human teleoperators…

Cited by 20SourcePDFScholar
2025

Magpie: Alignment Data Synthesis from Scratch by Prompting Aligned LLMs with Nothing

ICLR 2025poster

High-quality instruction data is critical for aligning large language models (LLMs). Although some models, such as Llama-3-Instruct, have open weights, their alignment data remain private, which hinders the democratization of AI. High human labor costs and a limited, predefined scope for prompting p…

2025

RewardBench: Evaluating Reward Models for Language Modeling

NAACL 2025findings

Reward models (RMs) are at the crux of successfully using RLHF to align pretrained models to human preferences, yet there has been relatively little study that focuses on evaluation of those models. Evaluating reward models presents an opportunity to understand the opaque technologies used for align…

2025

SafeChain: Safety of Language Models with Long Chain-of-Thought Reasoning Capabilities

ACL 2025finding

Emerging large reasoning models (LRMs), such as DeepSeek-R1 models, leverage long chain-of-thought (CoT) reasoning to generate structured intermediate steps, enhancing their reasoning capabilities. However, long CoT does not inherently guarantee safe outputs, potentially leading to harmful consequen…

Cited by 0SourcePDFScholar
2025

SimulBench: Evaluating Language Models with Creative Simulation Tasks

NAACL 2025findings

We introduce SimulBench, a benchmark designed to evaluate large language models (LLMs) across a diverse collection of creative simulation tasks, such as acting as a Linux terminal or playing text games with users. While these simulation tasks serve as effective measures of an LLM’s general intellige…

2025

Small Models Struggle to Learn from Strong Reasoners

ACL 2025finding

Large language models (LLMs) excel in complex reasoning tasks, and distilling their reasoning capabilities into smaller models has shown promise. However, we uncover an interesting phenomenon, which we term the Small Model Learnability Gap: small models (3B parameters) do not consistently benefit fr…

2025

Stronger Models are Not Always Stronger Teachers for Instruction Tuning

NAACL 2025long

Instruction tuning has been widely adopted to ensure large language models (LLMs) follow user instructions and engage with users meaningfully. The resulting instruction-following capabilities of LLMs heavily rely on the instruction datasets used for tuning. Recently, synthetic instruction datasets h…

2025

The BiGGen Bench: A Principled Benchmark for Fine-grained Evaluation of Language Models with Language Models

NAACL 2025long

As language models (LMs) become capable of handling a wide range of tasks, their evaluation is becoming as challenging as their development. Most generation benchmarks currently assess LMs using abstract evaluation criteria-like helpfulness and harmlessness-which often lack the flexibility and granu…

2025

The Good, The Bad, and The Greedy: Evaluation of LLMs Should Not Ignore Non-Determinism

NAACL 2025long

Current evaluations of large language models (LLMs) often overlook non-determinism, typically focusing on a single output per example. This limits our understanding of LLM performance variability in real-world applications. Our study addresses this issue by exploring key questions about the performa…

2025

VL-RewardBench: A Challenging Benchmark for Vision-Language Generative Reward Models

CVPR 2025highlight

Vision-language generative reward models (VL-GenRMs) play a crucial role in aligning and evaluating multimodal AI systems, yet their own evaluation remains under-explored. Current assessment methods primarily rely on AI-annotated preference labels from traditional VL tasks, which can introduce biase…

2025

WildBench: Benchmarking LLMs with Challenging Tasks from Real Users in the Wild

ICLR 2025spotlight

We introduce WildBench, an automated evaluation framework designed to benchmark large language models (LLMs) using challenging, real-world user queries. WildBench consists of 1,024 tasks carefully selected from over one million human-chatbot conversation logs. For automated evaluation with WildBench…

2025

ZebraLogic: On the Scaling Limits of LLMs for Logical Reasoning

ICML 2025poster

We investigate the logical reasoning capabilities of Large Language Models (LLMs) and their scalability across complex deductive tasks. Using ZebraLogic, a newly developed benchmark dataset of logic grid puzzles derived from constraint satisfaction problems (CSPs), we systematically evaluate LLM per…

Cited by 7SourcePDFScholar
2024

Agent Lumos: Unified and Modular Training for Open-Source Language Agents

ACL 2024long

Closed-source agents suffer from several issues such as a lack of affordability, transparency, and reproducibility, particularly on complex interactive tasks. This motivates the development of open-source alternatives. We introduce Lumos, one of the first frameworks for training open-source LLM-base…

2024

OpenCodeInterpreter: Integrating Code Generation with Execution and Refinement

ACL 2024findings

The introduction of large language models has significantly advanced code generation. However, open-source models often lack the execution capabilities and iterative refinement of advanced systems like the GPT-4 Code Interpreter. To address this, we introduce OpenCodeInterpreter, a family of open-so…

Cited by 127SourcePDFScholar
2024

Prometheus 2: An Open Source Language Model Specialized in Evaluating Other Language Models

EMNLP 2024main

Proprietary LMs such as GPT-4 are often employed to assess the quality of responses from various LMs. However, concerns including transparency, controllability, and affordability strongly motivate the development of open-source LMs specialized in evaluations. On the other hand, existing open evaluat…

2024

SafeDecoding: Defending against Jailbreak Attacks via Safety-Aware Decoding

ACL 2024long

As large language models (LLMs) become increasingly integrated into real-world applications such as code generation and chatbot assistance, extensive efforts have been made to align LLM behavior with human values, including safety. Jailbreak attacks, which aim to provoke unintended and unsafe behavi…

2024

Selective “Selective Prediction”: Reducing Unnecessary Abstention in Vision-Language Reasoning

ACL 2024findings

Selective prediction minimizes incorrect predictions from vision-language models (VLMs) by allowing them to abstain from answering when uncertain. However, when deploying a vision-language system with low tolerance for inaccurate predictions, selective prediction may be over-cautious and abstain too…

2024

The Unlocking Spell on Base LLMs: Rethinking Alignment via In-Context Learning

ICLR 2024poster

Alignment tuning has become the de facto standard practice for enabling base large language models (LLMs) to serve as open-domain AI assistants. The alignment tuning process typically involves instruction learning through supervised fine-tuning (SFT) and preference tuning via reinforcement learning…

Cited by 169SourcePDFScholar
2024

Trial and Error: Exploration-Based Trajectory Optimization of LLM Agents

ACL 2024long

Large Language Models (LLMs) have become integral components in various autonomous agent systems.In this study, we present an exploration-based trajectory optimization approach, referred to as ETO. This learning method is designed to enhance the performance of open LLM agents. Contrary to previous s…

2024

VideoScore: Building Automatic Metrics to Simulate Fine-grained Human Feedback for Video Generation

EMNLP 2024main

The recent years have witnessed great advances in video generation. However, the development of automatic video metrics is lagging significantly behind. None of the existing metric is able to provide reliable scores over generated videos. The main barrier is the lack of large-scale human-annotated d…

2024

WildGuard: Open One-stop Moderation Tools for Safety Risks, Jailbreaks, and Refusals of LLMs

NeurIPS 2024poster

We introduce WildGuard---an open, light-weight moderation tool for LLM safety that achieves three goals: (1) identifying malicious intent in user prompts, (2) detecting safety risks of model responses, and (3) determining model refusal rate. Together, WildGuard serves the increasing needs for automa…

2024

WildVision: Evaluating Vision-Language Models in the Wild with Human Preferences

NeurIPS 2024poster

Recent breakthroughs in vision-language models (VLMs) emphasize the necessity of benchmarking human preferences in real-world multimodal interactions. To address this gap, we launched WildVision-Arena (WV-Arena), an online platform that collects human preferences to evaluate VLMs. We curated WV-Benc…

Cited by 32SourcePDFScholar
2023

Faith and Fate: Limits of Transformers on Compositionality

NeurIPS 2023spotlight

Transformer large language models (LLMs) have sparked admiration for their exceptional performance on tasks that demand intricate multi-step reasoning. Yet, these models simultaneously show failures on surprisingly trivial problems. This begs the question: Are these errors incidental, or do they si…

2023

Inference-Time Policy Adapters (IPA): Tailoring Extreme-Scale LMs without Fine-tuning

EMNLP 2023long main

While extreme-scale language models have demonstrated exceptional performance on a variety of language tasks, the degree of control over these language models through pure prompting can often be limited. Directly fine-tuning such language models can be effective for tailoring them, but it can be eit…

Cited by 0SourcecodeScholar
2023

LLM-Blender: Ensembling Large Language Models with Pairwise Ranking and Generative Fusion

ACL 2023long

We present LLM-Blender, an ensembling framework designed to attain consistently superior performance by leveraging the diverse strengths of multiple open-source large language models (LLMs). Our framework consists of two modules: PairRanker and GenFuser, addressing the observation that optimal LLMs…

2023

NovaCOMET: Open Commonsense Foundation Models with Symbolic Knowledge Distillation

EMNLP 2023long findings

We present NovaCOMET, an open commonsense knowledge model, that combines the best aspects of knowledge and general task models. Compared to previous knowledge models, NovaCOMET allows open-format relations enabling direct application to reasoning tasks; compared to general task models like Flan-T5,…

Cited by 0SourceScholar
2023

On Grounded Planning for Embodied Tasks with Language Models

AAAI 2023technical

Language models (LMs) have demonstrated their capability in possessing commonsense knowledge of the physical world, a crucial aspect of performing tasks in everyday life. However, it remains unclear whether they have the capacity to generate grounded, executable plans for embodied tasks. This is a c…

Cited by 41SourcePDFScholar
2023

SwiftSage: A Generative Agent with Fast and Slow Thinking for Complex Interactive Tasks

NeurIPS 2023spotlight

We introduce SwiftSage, a novel agent framework inspired by the dual-process theory of human cognition, designed to excel in action planning for complex interactive reasoning tasks. SwiftSage integrates the strengths of behavior cloning and prompting large language models (LLMs) to enhance task comp…

Cited by 64SourcePDFScholar
2022

FedNLP: Benchmarking Federated Learning Methods for Natural Language Processing Tasks

NAACL 2022findings

Increasing concerns and regulations about data privacy and sparsity necessitate the study of privacy-preserving, decentralized learning methods for natural language processing (NLP) tasks. Federated learning (FL) provides promising approaches for a large number of clients (e.g., personal devices or…

2022

On Continual Model Refinement in Out-of-Distribution Data Streams

ACL 2022long

Real-world natural language processing (NLP) models need to be continually updated to fix the prediction errors in out-of-distribution (OOD) data streams while overcoming catastrophic forgetting. However, existing continual learning (CL) problem setups cannot cover such a realistic and complex scena…

Cited by 26SourcePDFScholar
2022

On the Robustness of Reading Comprehension Models to Entity Renaming

NAACL 2022long

We study the robustness of machine reading comprehension (MRC) models to entity renaming—do models make more wrong predictions when the same questions are asked about an entity whose name has been changed? Such failures imply that models overly rely on entity information to answer questions, and thu…

2022

Reflect, Not Reflex: Inference-Based Common Ground Improves Dialogue Response Quality

EMNLP 2022main

Human communication relies on common ground (CG), the mutual knowledge and beliefs shared by participants, to produce coherent and interesting conversations. In this paper, we demonstrate that current response generation (RG) models produce generic and dull responses in dialogues because they act re…

Cited by 30SourcePDFScholar
2022

Unsupervised Cross-Task Generalization via Retrieval Augmentation

NeurIPS 2022accept

Humans can perform unseen tasks by recalling relevant skills acquired previously and then generalizing them to the target tasks, even if there is no supervision at all. In this paper, we aim to improve this kind of cross-task generalization ability of massive multi-task language models, such as T0 a…

2021

Common Sense Beyond English: Evaluating and Improving Multilingual Language Models for Commonsense Reasoning

ACL 2021long

Commonsense reasoning research has so far been limited to English. We aim to evaluate and improve popular multilingual language models (ML-LMs) to help advance commonsense reasoning (CSR) beyond English. We collect the Mickey corpus, consisting of 561k sentences in 11 different languages, which can…

2021

CrossFit: A Few-shot Learning Challenge for Cross-task Generalization in NLP

EMNLP 2021main

Humans can learn a new language task efficiently with only few examples, by leveraging their knowledge obtained when learning prior tasks. In this paper, we explore whether and how such cross-task generalization ability can be acquired, and further applied to build better few-shot learners across di…

2021

Differentiable Open-Ended Commonsense Reasoning

NAACL 2021long

Current commonsense reasoning research focuses on developing models that use commonsense knowledge to answer multiple-choice questions. However, systems designed to answer multiple-choice questions may not be useful in applications that do not provide a small list of candidate answers to choose from…

Cited by 44SourcePDFScholar
2021

Learn Continually, Generalize Rapidly: Lifelong Knowledge Accumulation for Few-shot Learning

EMNLP 2021finding

The ability to continuously expand knowledge over time and utilize it to rapidly generalize to new tasks is a key feature of human linguistic intelligence. Existing models that pursue rapid generalization to new tasks (e.g., few-shot learning methods), however, are mostly trained in a single shot on…

2021

Probing Commonsense Explanation in Dialogue Response Generation

EMNLP 2021finding

Humans use commonsense reasoning (CSR) implicitly to produce natural and coherent responses in conversations. Aiming to close the gap between current response generation (RG) models and human communication abilities, we want to understand why RG models respond as they do by probing RG model’s unders…

Cited by 19SourcePDFScholar
2021

RICA: Evaluating Robust Inference Capabilities Based on Commonsense Axioms

EMNLP 2021main

Pre-trained language models (PTLMs) have achieved impressive performance on commonsense inference benchmarks, but their ability to employ commonsense to make robust inferences, which is crucial for effective communications with humans, is debated. In the pursuit of advancing fluid human-AI communica…

2021

RockNER: A Simple Method to Create Adversarial Examples for Evaluating the Robustness of Named Entity Recognition Models

EMNLP 2021main

To audit the robustness of named entity recognition (NER) models, we propose RockNER, a simple yet effective method to create natural adversarial examples. Specifically, at the entity level, we replace target entities with other entities of the same semantic class in Wikidata; at the context level,…