activity
20132026
most citedEnd-to-End Neural Ad-hoc Ranking with Kernel Pooling

575 citations · 1.7k across the 39 of their papers we have counts for

collaborators

40 papers

cs.IR2026

Agentic Search in the Wild: Intents and Trajectory Dynamics from 14M+ Real Search Requests

Jingjie Ning, João Coelho, Yibo Kong +5

LLM-powered search agents are increasingly being used for multi-step information seeking tasks, yet the IR community lacks empirical understanding of how agentic search sessions un…

cs.IR2025★ 1 cited

DeepResearchGym: A Free, Transparent, and Reproducible Evaluation Sandbox for Deep Research

João Coelho, Jingjie Ning, Jingyuan He +8

Deep research systems represent an emerging class of agentic information retrieval methods that generate comprehensive and well-supported reports to complex queries. However, most…

cs.IR2024

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

João Coelho, Bruno Martins, João Magalhães +2

This study investigates the existence of positional biases in Transformer-based models for text representation learning, particularly in the context of web document retrieval. We b…

cs.IR2024

Building Retrieval Systems for the ClueWeb22-B Corpus

Harshit Mehrotra, Jamie Callan, Zhen Fan

The ClueWeb22 dataset containing nearly 10 billion documents was released in 2022 to support academic and industry research. The goal of this project was to build retrieval baselin…

cs.SE2023

Multi-Objective Improvement of Android Applications

James Callan, Justyna Petke

Non-functional properties, such as runtime or memory use, are important to mobile app users and developers, as they affect user experience. Previous work on automated improvement o…

cs.CL2023★ 18 cited

Active Retrieval Augmented Generation

Zhengbao Jiang, Frank F. Xu, Luyu Gao +6

Despite the remarkable ability of large language models (LMs) to comprehend and generate language, they have a tendency to hallucinate and create factually inaccurate output. Augme…

cs.IR2022★ 21 cited

Precise Zero-Shot Dense Retrieval without Relevance Labels

Luyu Gao, Xueguang Ma, Jimmy Lin +1

While dense retrieval has been shown effective and efficient across tasks and languages, it remains difficult to create effective fully zero-shot dense retrieval systems when no re…

cs.CL2022★ 1 cited

Retrieval as Attention: End-to-end Learning of Retrieval and Reading within a Single Transformer

Zhengbao Jiang, Luyu Gao, Jun Araki +4

Systems for knowledge-intensive tasks such as open-domain question answering (QA) usually consist of two stages: efficient retrieval of relevant documents from a large corpus and d…

cs.IR2022★ 5 cited

ClueWeb22: 10 Billion Web Documents with Visual and Semantic Information

Arnold Overwijk, Chenyan Xiong, Xiao Liu +2

ClueWeb22, the newest iteration of the ClueWeb line of datasets, provides 10 billion web pages affiliated with rich information. Its design was influenced by the need for a high qu…

cs.CL2022★ 105 cited

PAL: Program-aided Language Models

Luyu Gao, Aman Madaan, Shuyan Zhou +5

Large language models (LLMs) have recently demonstrated an impressive ability to perform arithmetic and symbolic reasoning tasks, when provided with a few examples at test time ("f…

cs.IR2022★ 7 cited

Long Document Re-ranking with Modular Re-ranker

Luyu Gao, Jamie Callan

Long document re-ranking has been a challenging problem for neural re-rankers based on deep language models like BERT. Early work breaks the documents into short passage-like chunk…

cs.IR2022★ 28 cited

Tevatron: An Efficient and Flexible Toolkit for Dense Retrieval

Luyu Gao, Xueguang Ma, Jimmy Lin +1

Recent rapid advancements in deep pre-trained language models and the introductions of large datasets have powered research in embedding-based dense retrieval. While several good r…

cs.IR2021★ 1 cited

Improving Query Representations for Dense Retrieval with Pseudo Relevance Feedback

HongChien Yu, Chenyan Xiong, Jamie Callan

Dense retrieval systems conduct first-stage retrieval using embedded representations and simple similarity metrics to match a query to documents. Its effectiveness depends on encod…

cs.IR2021★ 54 cited

Unsupervised Corpus Aware Language Model Pre-training for Dense Passage Retrieval

Luyu Gao, Jamie Callan

Recent research demonstrates the effectiveness of using fine-tuned language models~(LM) for dense retrieval. However, dense retrievers are hard to train, typically requiring heavil…

cs.IR2021★ 10 cited

COIL: Revisit Exact Lexical Match in Information Retrieval with Contextualized Inverted List

Luyu Gao, Zhuyun Dai, Jamie Callan

Classical information retrieval systems such as BM25 rely on exact lexical match and carry out search efficiently with inverted list index. Recent neural IR models shifts towards s…

cs.CL2021★ 8 cited

Condenser: a Pre-training Architecture for Dense Retrieval

Luyu Gao, Jamie Callan

Pre-trained Transformer language models (LM) have become go-to text representation encoders. Prior research fine-tunes deep LMs to encode text sequences such as sentences and passa…

cs.IR2021★ 8 cited

Rethink Training of BERT Rerankers in Multi-Stage Retrieval Pipeline

Luyu Gao, Zhuyun Dai, Jamie Callan

Pre-trained deep language models~(LM) have advanced the state-of-the-art of text retrieval. Rerankers fine-tuned from deep LM estimates candidate relevance based on rich contextual…

cs.IR2021

Assessing the Benefits of Model Ensembles in Neural Re-Ranking for Passage Retrieval

Luís Borges, Bruno Martins, Jamie Callan

Our work aimed at experimentally assessing the benefits of model ensembling within the context of neural methods for passage reranking. Starting from relatively standard neural mod…

cs.IR2021★ 3 cited

PGT: Pseudo Relevance Feedback Using a Graph-Based Transformer

HongChien Yu, Zhuyun Dai, Jamie Callan

Most research on pseudo relevance feedback (PRF) has been done in vector space and probabilistic retrieval models. This paper shows that Transformer-based rerankers can also benefi…

cs.LG2021★ 5 cited

Scaling Deep Contrastive Learning Batch Size under Memory Limited Setup

Luyu Gao, Yunyi Zhang, Jiawei Han +1

Contrastive learning has been applied successfully to learn vector representations of text. Previous research demonstrated that learning high-quality representations benefits from…

cs.IR2020★ 5 cited

Generating Categories for Sets of Entities

Shuo Zhang, Krisztian Balog, Jamie Callan

Category systems are central components of knowledge bases, as they provide a hierarchical grouping of semantically related concepts and entities. They are a unique and valuable re…

cs.LG2020★ 12 cited

Ranking Clarification Questions via Natural Language Inference

Vaibhav Kumar, Vikas Raunak, Jamie Callan

Given a natural language query, teaching machines to ask clarifying questions is of immense utility in practical natural language processing systems. Such interactions could help i…

cs.IR2020★ 25 cited

Understanding BERT Rankers Under Distillation

Luyu Gao, Zhuyun Dai, Jamie Callan

Deep language models such as BERT pre-trained on large corpus have given a huge performance boost to the state-of-the-art information retrieval ranking systems. Knowledge embedded…

cs.IR2020★ 14 cited

Summarizing and Exploring Tabular Data in Conversational Search

Shuo Zhang, Zhuyun Dai, Krisztian Balog +1

Tabular data provide answers to a significant portion of search queries. However, reciting an entire result table is impractical in conversational search systems. We propose to gen…