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Chenyan Xiong

48 accepted papers

2026

Spectral Guidance for Flexible and Efficient Control of Diffusion Models

ICML 2026poster

We introduce Spectral Guidance, a framework for controlling diffusion models by leveraging the intrinsic geometry of the generative process. As data is progressively corrupted by noise, only a small number of features remain informative for control. We characterize them as the singular functions of …

Cited by 0SourceScholar
2026

What Generative Search Engines Like and How to Optimize Web Content Cooperatively

ICLR 2026poster

By employing large language models (LLMs) to retrieve documents and generate natural language responses, Generative Engines, such as Google AI overview and ChatGPT, provide significantly enhanced user experiences and have rapidly become the new form of search. Their rapid adoption also drives the ne…

Cited by 0SourcecodeScholar
2025

DATE-LM: Benchmarking Data Attribution Evaluation for Large Language Models

NeurIPS 2025poster

Data attribution methods quantify the influence of training data on model outputs and are becoming increasingly relevant for a wide range of LLM research and applications, including dataset curation, model interpretability, data valuation. However, there remain critical gaps in systematic LLM-centri…

Cited by 0SourceScholar
2025

Fact-Aware Multimodal Retrieval Augmentation for Accurate Medical Radiology Report Generation

NAACL 2025long

Multimodal foundation models hold significant potential for automating radiology report generation, thereby assisting clinicians in diagnosing cardiac diseases. However, generated reports often suffer from serious factual inaccuracy. In this paper, we introduce a fact-aware multimodal retrieval-augm…

Cited by 14SourcePDFScholar
2025

Fairshare Data Pricing via Data Valuation for Large Language Models

NeurIPS 2025poster

Training data is the backbone of large language models (LLMs), yet today’s data markets often operate under exploitative pricing -- sourcing data from marginalized groups with little pay or recognition. This paper introduces a theoretical framework for LLM data markets, modeling the strategic intera…

Cited by 0SourceScholar
2025

Group-Level Data Selection for Efficient Pretraining

NeurIPS 2025poster

The efficiency and quality of language model pretraining are largely determined by the way pretraining data are selected. In this paper, we introduce *Group-MATES*, an efficient group-level data selection approach to optimize the speed-quality frontier of language model pretraining. Specifically, Gr…

Cited by 0SourcecodeScholar
2025

Harnessing Webpage UIs for Text-Rich Visual Understanding

ICLR 2025poster

Text-rich visual understanding—the ability to interpret both textual content and visual elements within a scene—is crucial for multimodal large language models (MLLMs) to effectively interact with structured environments. We propose leveraging webpage UIs as a naturally structured and diverse data s…

Cited by 3SourcePDFScholar
2025

Montessori-Instruct: Generate Influential Training Data Tailored for Student Learning

ICLR 2025poster

Synthetic data has been widely used to train large language models, but their generative nature inevitably introduces noisy, non-informative, and misleading learning signals. In this paper, we propose Montessori-Instruct, a novel data synthesis framework that tailors the data synthesis ability of th…

2025

ORBIT - Open Recommendation Benchmark for Reproducible Research with Hidden Tests

NeurIPS 2025poster

Recommender systems are among the most impactful AI applications, interacting with billions of users every day, guiding them to relevant products, services, or information tailored to their preferences. However, the research and development of recommender systems are hindered by existing datasets th…

Cited by 0SourceScholar
2025

On the Feasibility of In-Context Probing for Data Attribution

NAACL 2025findings

Data attribution methods are used to measure the contribution of training data towards model outputs, and have several important applications in areas such as dataset curation and model interpretability. However, many standard data attribution methods, such as influence functions, utilize model grad…

Cited by 0SourcePDFScholar
2025

ParamMute: Suppressing Knowledge-Critical FFNs for Faithful Retrieval-Augmented Generation

NeurIPS 2025poster

Large language models (LLMs) integrated with retrieval-augmented generation (RAG) have improved factuality by grounding outputs in external evidence. However, they remain susceptible to unfaithful generation, where outputs contradict retrieved context despite its relevance and accuracy. Existing app…

Cited by 0SourcecodeScholar
2025

RAG-DDR: Optimizing Retrieval-Augmented Generation Using Differentiable Data Rewards

ICLR 2025poster

Retrieval-Augmented Generation (RAG) has proven its effectiveness in mitigating hallucinations in Large Language Models (LLMs) by retrieving knowledge from external resources. To adapt LLMs for the RAG systems, current approaches use instruction tuning to optimize LLMs, improving their ability to ut…

2025

ResearchArena: Benchmarking Large Language Models’ Ability to Collect and Organize Information as Research Agents

EMNLP 2025

Large language models (LLMs) excel across many natural language processing tasks but face challenges in domain-specific, analytical tasks such as conducting research surveys. This study introduces ResearchArena, a benchmark designed to evaluate LLMs’ capabilities in conducting academic surveys—a fou

2025

Understand User Opinions of Large Language Models via LLM-Powered In-the-Moment User Experience Interviews

ACL 2025finding

Which large language model (LLM) is better? Every evaluation tells a story, but what do users really think about current LLMs? This paper presents CLUE, an LLM-powered interviewer that conducts in-the-moment user experience interviews, right after users interact with LLMs, and automatically gathers…

2024

Cleaner Pretraining Corpus Curation with Neural Web Scraping

ACL 2024short

The web contains large-scale, diverse, and abundant information to satisfy the information-seeking needs of humans. Through meticulous data collection, preprocessing, and curation, webpages can be used as a fundamental data resource for language model pretraining. However, when confronted with the p…

2024

Dwell in the Beginning: How Language Models Embed Long Documents for Dense Retrieval

ACL 2024short

This study investigates the existence of positional biases in Transformer-based language models for text representation learning, particularly in the context of web document retrieval. We build on previous research that demonstrated loss of information in the middle of input sequences for causal lan…

2024

ED-Copilot: Reduce Emergency Department Wait Time with Language Model Diagnostic Assistance

ICML 2024poster

In the emergency department (ED), patients undergo triage and multiple laboratory tests before diagnosis. This time-consuming process causes ED crowding which impacts patient mortality, medical errors, staff burnout, etc. This work proposes (time) *cost-effective diagnostic assistance* that leverage…

2024

Fusion-in-T5: Unifying Variant Signals for Simple and Effective Document Ranking with Attention Fusion

COLING 2024main

Common document ranking pipelines in search systems are cascade systems that involve multiple ranking layers to integrate different information step-by-step. In this paper, we propose a novel re-ranker Fusion-in-T5 (FiT5), which integrates text matching information, ranking features, and global docu…

2024

MARVEL: Unlocking the Multi-Modal Capability of Dense Retrieval via Visual Module Plugin

ACL 2024long

This paper proposes Multi-modAl Retrieval model via Visual modulE pLugin (MARVEL), which learns an embedding space for queries and multi-modal documents to conduct retrieval. MARVEL encodes queries and multi-modal documents with a unified encoder model, which helps to alleviate the modality gap betw…

2024

MATES: Model-Aware Data Selection for Efficient Pretraining with Data Influence Models

NeurIPS 2024poster

Pretraining data selection has the potential to improve language model pretraining efficiency by utilizing higher-quality data from massive web data corpora. Current data selection methods, which rely on either hand-crafted rules or larger reference models, are conducted statically and do not captur…

2024

RAGViz: Diagnose and Visualize Retrieval-Augmented Generation

EMNLP 2024system demonstrations

Retrieval-augmented generation (RAG) combines knowledge from domain-specific sources into large language models to ground answer generation. Current RAG systems lack customizable visibility on the context documents and the model’s attentiveness towards such documents. We propose RAGViz, a RAG diagno…

2024

Toolink: Linking Toolkit Creation and Using through Chain-of-Solving on Open-Source Model

NAACL 2024long

Large Language Models (LLMs) have demonstrated remarkable progress in utilizing tools, but their closed-source nature and high inference costs pose limitations on their adaptability, necessitating a valid method that leverages smaller, open-sourced models. In this paper, we introduce Toolink, a comp…

2023

Augmentation-Adapted Retriever Improves Generalization of Language Models as Generic Plug-In

ACL 2023long

Retrieval augmentation can aid language models (LMs) in knowledge-intensive tasks by supplying them with external information. Prior works on retrieval augmentation usually jointly fine-tune the retriever and the LM, making them closely coupled. In this paper, we explore the scheme of generic retrie…

2023

Augmenting Zero-Shot Dense Retrievers with Plug-in Mixture-of-Memories

EMNLP 2023long main

In this paper we improve the zero-shot generalization ability of language models via Mixture-Of-Memory Augmentation (MoMA), a mechanism that retrieves augmentation documents from multiple information corpora (external memories), with the option to ''plug in'' unseen memory at inference time. We deve…

Cited by 0SourcecodeScholar
2023

CompleQA: Benchmarking the Impacts of Knowledge Graph Completion Methods on Question Answering

EMNLP 2023short findings

How much success in Knowledge Graph Completion (KGC) would translate into the performance enhancement in downstream tasks is an important question that has not been studied in depth. In this paper, we introduce a novel benchmark, namely CompleQA, to comprehensively assess the influence of representa…

Cited by 0SourceScholar
2023

Model-Generated Pretraining Signals Improves Zero-Shot Generalization of Text-to-Text Transformers

ACL 2023long

This paper explores the effectiveness of model-generated signals in improving zero-shot generalization of text-to-text Transformers such as T5. We study various designs to pretrain T5 using an auxiliary model to construct more challenging token replacements for the main model to denoise. Key aspects…

2023

Structure-Aware Language Model Pretraining Improves Dense Retrieval on Structured Data

ACL 2023findings

This paper presents Structure Aware Dense Retrieval (SANTA) model, which encodes user queries and structured data in one universal embedding space for retrieving structured data. SANTA proposes two pretraining methods to make language models structure-aware and learn effective representations for st…

2023

Universal Vision-Language Dense Retrieval: Learning A Unified Representation Space for Multi-Modal Retrieval

ICLR 2023poster

This paper presents Universal Vision-Language Dense Retrieval (UniVL-DR), which builds a unified model for multi-modal retrieval. UniVL-DR encodes queries and multi-modality resources in an embedding space for searching candidates from different modalities. To learn a unified embedding space for mul…

2022

COCO-DR: Combating the Distribution Shift in Zero-Shot Dense Retrieval with Contrastive and Distributionally Robust Learning

EMNLP 2022main

We present a new zero-shot dense retrieval (ZeroDR) method, COCO-DR, to improve the generalization ability of dense retrieval by combating the distribution shifts between source training tasks and target scenarios. To mitigate the impact of document differences, COCO-DR continues pretraining the lan…

2022

Dimension Reduction for Efficient Dense Retrieval via Conditional Autoencoder

EMNLP 2022main

Dense retrievers encode queries and documents and map them in an embedding space using pre-trained language models. These embeddings need to be high-dimensional to fit training signals and guarantee the retrieval effectiveness of dense retrievers. However, these high-dimensional embeddings lead to l…

2022

Pretraining Text Encoders with Adversarial Mixture of Training Signal Generators

ICLR 2022poster

We present a new framework AMOS that pretrains text encoders with an Adversarial learning curriculum via a Mixture Of Signals from multiple auxiliary generators. Following ELECTRA-style pretraining, the main encoder is trained as a discriminator to detect replaced tokens generated by auxiliary maske…

2022

Reduce Catastrophic Forgetting of Dense Retrieval Training with Teleportation Negatives

EMNLP 2022main

In this paper, we investigate the instability in the standard dense retrieval training, which iterates between model training and hard negative selection using the being-trained model. We show the catastrophic forgetting phenomena behind the training instability, where models learn and forget differ…

2022

Zero-Shot Dense Retrieval with Momentum Adversarial Domain Invariant Representations

ACL 2022findings

Dense retrieval (DR) methods conduct text retrieval by first encoding texts in the embedding space and then matching them by nearest neighbor search. This requires strong locality properties from the representation space, e.g., close allocations of each small group of relevant texts, which are hard…

2021

Approximate Nearest Neighbor Negative Contrastive Learning for Dense Text Retrieval

ICLR 2021poster

Conducting text retrieval in a learned dense representation space has many intriguing advantages. Yet dense retrieval (DR) often underperforms word-based sparse retrieval. In this paper, we first theoretically show the bottleneck of dense retrieval is the domination of uninformative negatives sample…

2021

COCO-LM: Correcting and Contrasting Text Sequences for Language Model Pretraining

NeurIPS 2021poster

We present a self-supervised learning framework, COCO-LM, that pretrains Language Models by COrrecting and COntrasting corrupted text sequences. Following ELECTRA-style pretraining, COCO-LM employs an auxiliary language model to corrupt text sequences, upon which it constructs two new tasks for pret…

2021

Data Augmentation for Abstractive Query-Focused Multi-Document Summarization

AAAI 2021technical

The progress in Query-focused Multi-Document Summarization (QMDS) has been limited by the lack of sufficient largescale high-quality training datasets. We present two QMDS training datasets, which we construct using two data augmentation methods: (1) transferring the commonly used single-document CN…

2021

Distantly-Supervised Dense Retrieval Enables Open-Domain Question Answering without Evidence Annotation

EMNLP 2021main

Open-domain question answering answers a question based on evidence retrieved from a large corpus. State-of-the-art neural approaches require intermediate evidence annotations for training. However, such intermediate annotations are expensive, and methods that rely on them cannot transfer to the mor…

2021

Few-Shot Text Ranking with Meta Adapted Synthetic Weak Supervision

ACL 2021long

The effectiveness of Neural Information Retrieval (Neu-IR) often depends on a large scale of in-domain relevance training signals, which are not always available in real-world ranking scenarios. To democratize the benefits of Neu-IR, this paper presents MetaAdaptRank, a domain adaptive learning meth…

2021

Less is More: Pretrain a Strong Siamese Encoder for Dense Text Retrieval Using a Weak Decoder

EMNLP 2021main

Dense retrieval requires high-quality text sequence embeddings to support effective search in the representation space. Autoencoder-based language models are appealing in dense retrieval as they train the encoder to output high-quality embedding that can reconstruct the input texts. However, in this…

2021

Multi-Step Reasoning Over Unstructured Text with Beam Dense Retrieval

NAACL 2021long

Complex question answering often requires finding a reasoning chain that consists of multiple evidence pieces. Current approaches incorporate the strengths of structured knowledge and unstructured text, assuming text corpora is semi-structured. Building on dense retrieval methods, we propose a new m…

2021

TIAGE: A Benchmark for Topic-Shift Aware Dialog Modeling

EMNLP 2021finding

Human conversations naturally evolve around different topics and fluently move between them. In research on dialog systems, the ability to actively and smoothly transition to new topics is often ignored. In this paper we introduce TIAGE, a new topic-shift aware dialog benchmark constructed utilizing…

2020

Towards Interpretable Natural Language Understanding with Explanations as Latent Variables

NeurIPS 2020poster

Recently generating natural language explanations has shown very promising results in not only offering interpretable explanations but also providing additional information and supervision for prediction. However, existing approaches usually require a large set of human annotated explanations for tr…

2020

Transformer-XH: Multi-Evidence Reasoning with eXtra Hop Attention

ICLR 2020poster

Transformers have achieved new heights modeling natural language as a sequence of text tokens. However, in many real world scenarios, textual data inherently exhibits structures beyond a linear sequence such as trees and graphs; many tasks require reasoning with evidence scattered across multiple pi…

Cited by 132SourcecodeScholar