PLAID-PRF: Pseudo-Relevance Feedback with Centroid-like Tokens in PLAID
Abstract
Multi-vector dense retrieval models, such as ColBERT, achieve strong retrieval effectiveness by modelling fine-grained token-level interactions between queries and documents. Methods such as PLAID use centroid-based quantisation of each token's vector to reduce the index size and speed up retrieval while maintaining strong effectiveness. In this work, we introduce PLAID-PRF, a method that performs Pseudo-Relevance Feedback (PRF) over PLAID to reformulate ColBERT's query vectors based on the top-retrieved results. In contrast with prior methods that perform PRF on multi-vector retrieval models, PLAID-PRF keeps computational costs low by leveraging the internal PLAID centroid vectors, treating them similarly to tokens in traditional PRF methods. The method selects a small and diverse set of high-utility expansion vectors and appends them to the original query, rerunning PLAID to refine both candidate generation and final scoring. Extensive experiments on the standard in-domain MSMARCO and four out-of-domain BEIR benchmarks show that PLAID-PRF consistently improves retrieval effectiveness over various baselines. In particular, PLAID-PRF improves over PLAID by up to 4.3% nDCG@10 and 7.3% MRR@10, while introducing substantially less computation overhead than prior PRF methods. The results demonstrate that our proposed centroid-aware PRF method offers an effective and lightweight mechanism to improve the quality of top-ranked retrieved results. Overall, this work enables effective and efficient feedback-aware late-interaction retrieval without expensive query-time document-token clustering.
Assigned reviewers
| # | Reviewer | Match | Why (closest evidence publications in the taxonomy) | |
|---|---|---|---|---|
| 1 | Xueguang Ma | 70 | 81 Gosling Grows Up: Retrieval with Learned Dense and Sparse Representations Using Anserini (2025) Learned Sparse Retrieval Efficiency 81 SLIM: Sparsified Late Interaction for Multi-Vector Retrieval with Inverted Indexes (2023) Learned Sparse Retrieval Efficiency 80 LACONIC: Dense-Level Effectiveness for Scalable Sparse Retrieval via a Two-Phase Training Curriculum (2026) Learned Sparse Retrieval Efficiency |
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| 2 | Shengyao Zhuang | 58 | 80 LACONIC: Dense-Level Effectiveness for Scalable Sparse Retrieval via a Two-Phase Training Curriculum (2026) Learned Sparse Retrieval Efficiency 72 Improving Query Representations for Dense Retrieval with Pseudo Relevance Feedback: A Reproducibility Study (2022) Query Reformulation and Expansion 72 Revisiting Document Expansion and Filtering for Effective First-Stage Retrieval (2024) Query Reformulation and Expansion |
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| 3 | Sheng-Chieh Lin | 54 | 81 Pyserini: A Python Toolkit for Reproducible Information Retrieval Research with Sparse and Dense Representations (2021) Learned Sparse Retrieval Efficiency 81 SLIM: Sparsified Late Interaction for Multi-Vector Retrieval with Inverted Indexes (2023) Learned Sparse Retrieval Efficiency 81 CITADEL: Conditional Token Interaction via Dynamic Lexical Routing for Efficient and Effective Multi-Vector Retrieval (2023) Learned Sparse Retrieval Efficiency |
Area chair
| Area chair | Match | |
|---|---|---|
| Chenyan Xiong | 47 |
Area-chair candidates (6)
| Chenyan Xiong assigned | 47 | 15 papers | |
| Xiaoxue Zang | 46 | 4 papers | |
| Fernando Diaz 0001 | 44 | 12 papers | |
| Jun Xu 0001 | 41 | 2 papers | |
| Xiaoyi Zeng | 40 | 11 papers | |
| Hongjin Qian | 39 | 12 papers |
Candidates from the panel ranked by match score
| # | Reviewer | Match | Load | Why | |
|---|---|---|---|---|---|
| 1 | Antonio Mallia COI: co-author | 79 | 3 | 81 Faster Learned Sparse Retrieval with Guided Traversal (2022) Learned Sparse Retrieval Efficiency 81 Faster Learned Sparse Retrieval with Block-Max Pruning (2024) Learned Sparse Retrieval Efficiency |
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| 2 | Xiao Wang 0043 COI: author | 77 | 3 | 81 Reproducibility, Replicability, and Insights into Dense Multi-Representation Retrieval Models: from ColBERT to Col (2023) Learned Sparse Retrieval Efficiency 81 An Inspection of the Reproducibility and Replicability of TCT-ColBERT (2022) Learned Sparse Retrieval Efficiency |
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| 3 | Franco Maria Nardini COI: co-author | 76 | 3 | 81 Efficient Inverted Indexes for Approximate Retrieval over Learned Sparse Representations (2024) Learned Sparse Retrieval Efficiency 81 Pairing Clustered Inverted Indexes with κ-NN Graphs for Fast Approximate Retrieval over Learned Sparse Representations (2024) Learned Sparse Retrieval Efficiency |
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| 4 | Xueguang Ma assigned | 70 | 3 | 81 Gosling Grows Up: Retrieval with Learned Dense and Sparse Representations Using Anserini (2025) Learned Sparse Retrieval Efficiency 81 SLIM: Sparsified Late Interaction for Multi-Vector Retrieval with Inverted Indexes (2023) Learned Sparse Retrieval Efficiency |
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| 5 | Huiqiang Jiang | 69 | 3 | 72 RetrievalAttention: Accelerating Long-Context LLM Inference via Vector Retrieval (2025) Learned Sparse Retrieval Efficiency 72 RetroInfer: A Vector Storage Engine for Scalable Long-Context LLM Inference (2026) Learned Sparse Retrieval Efficiency |
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| 6 | Sebastian Bruch 0001 | 64 | 3 | 81 Forward Index Compression for Learned Sparse Retrieval (2026) Learned Sparse Retrieval Efficiency 72 Efficient Inverted Indexes for Approximate Retrieval over Learned Sparse Representations (2024) Learned Sparse Retrieval Efficiency |
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| 7 | Shengyao Zhuang assigned | 58 | 3 | 80 LACONIC: Dense-Level Effectiveness for Scalable Sparse Retrieval via a Two-Phase Training Curriculum (2026) Learned Sparse Retrieval Efficiency 72 Improving Query Representations for Dense Retrieval with Pseudo Relevance Feedback: A Reproducibility Study (2022) Query Reformulation and Expansion |
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| 8 | Jurek Leonhardt | 56 | 3 | 75 Efficient Neural Ranking using Forward Indexes (2022) Learned Sparse Retrieval Efficiency 75 Efficient Neural Ranking Using Forward Indexes and Lightweight Encoders (2024) Learned Sparse Retrieval Efficiency |
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| 9 | Negar Arabzadeh | 55 | 3 | 61 Predicting Efficiency/Effectiveness Trade-offs for Dense vs. Sparse Retrieval Strategy Selection (2021) Efficient Retrieval and Indexing 58 Enhanced Retrieval Effectiveness through Selective Query Generation (2024) Query Reformulation and Expansion |
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| 10 | Sheng-Chieh Lin assigned | 54 | 3 | 81 Pyserini: A Python Toolkit for Reproducible Information Retrieval Research with Sparse and Dense Representations (2021) Learned Sparse Retrieval Efficiency 81 SLIM: Sparsified Late Interaction for Multi-Vector Retrieval with Inverted Indexes (2023) Learned Sparse Retrieval Efficiency |
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| 11 | Jingtao Zhan | 52 | 3 | 81 Joint Optimization of Multi-vector Representation with Product Quantization (2022) Learned Sparse Retrieval Efficiency 52 Jointly Optimizing Query Encoder and Product Quantization to Improve Retrieval Performance (2021) Approximate Nearest Neighbor Search |
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| 12 | Daiting Shi | 48 | 3 | 75 Pre-trained Language Model-based Retrieval and Ranking for Web Search (2023) Learned Sparse Retrieval Efficiency 73 Pre-trained Language Model based Ranking in Baidu Search (2021) Learned Sparse Retrieval Efficiency |
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| 13 | Xinyu Ma 0001 | 48 | 3 | 62 Probe-and-Fetch: Dynamic KV Cache Pruning for Accelerated Long-Context Inference in Web-Scale AI Search (2026) Efficient and Long-Context RAG 57 Replication and Exploration of Generative Retrieval over Dynamic Corpora (2025) Generative Retrieval |
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| 16 | Jialong Wu 0007 | 44 | 3 | 72 SCOPE: Optimizing Key-Value Cache Compression in Long-context Generation (2025) Learned Sparse Retrieval Efficiency 56 AdaRewriter: Unleashing the Power of Prompting-based Conversational Query Reformulation via Test-Time Adaptation (2025) Query Reformulation and Expansion |
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| 18 | Ruqing Zhang 0001 | 44 | 3 | 50 PROP: Pre-training with Representative Words Prediction for Ad-hoc Retrieval (2021) Sparse and Dense Retrieval Encoders 50 B-PROP: Bootstrapped Pre-training with Representative Words Prediction for Ad-hoc Retrieval (2021) Sparse and Dense Retrieval Encoders |
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| 19 | Yuchen Li 0006 | 43 | 3 | 62 Probe-and-Fetch: Dynamic KV Cache Pruning for Accelerated Long-Context Inference in Web-Scale AI Search (2026) Efficient and Long-Context RAG 45 COLTR: Semi-Supervised Learning to Rank With Co-Training and Over-Parameterization for Web Search (2023) Web-Scale Learning to Rank |
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| 20 | Falk Scholer COI: co-author | 43 | 3 | 58 Query association for effective retrieval (2002) Query Reformulation and Expansion 51 Can Generative LLMs Create Query Variants for Test Collections? An Exploratory Study (2023) Query Reformulation and Expansion |
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| 21 | Corby Rosset | 43 | 3 | 72 Optimizing Query Evaluations Using Reinforcement Learning for Web Search (2018) Efficient Retrieval and Indexing 66 Dodo: Dynamic Contextual Compression for Decoder-only LMs (2024) Learned Sparse Retrieval Efficiency |
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| 22 | Gustavo Penha | 42 | 3 | 63 Improving Content Retrievability in Search with Controllable Query Generation (2023) Query Reformulation and Expansion 55 Evaluating the Robustness of Retrieval Pipelines with Query Variation Generators (2022) Query Reformulation and Expansion |
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| 23 | Keping Bi | 42 | 3 | 52 Reproducibility Analysis and Enhancements for Multi-aspect Dense Retriever with Aspect Learning (2024) Retrieval Toolkits and Reproducibility 51 A Multi-Granularity-Aware Aspect Learning Model for Multi-Aspect Dense Retrieval (2024) Sparse and Dense Retrieval Encoders |
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| 24 | Venktesh V COI: co-author | 41 | 3 | 71 Breaking the Lens of the Telescope: Online Relevance Estimation over Large Retrieval Sets (2025) Learned Sparse Retrieval Efficiency 51 Understanding the User: An Intent-Based Ranking Dataset (2024) Query Reformulation and Expansion |
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| 26 | Idan Szpektor | 41 | 3 | 58 Improving recommendation for long-tail queries via templates (2011) Query Reformulation and Expansion 58 From query to question in one click: suggesting synthetic questions to searchers (2013) Query Reformulation and Expansion |
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| 27 | Leif Azzopardi | 41 | 3 | 54 Improving sentence retrieval with an importance prior (2010) Query and Document Representation Enhancement 45 Query Variation Performance Prediction for Systematic Reviews (2018) Query Performance Prediction |
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| 28 | Jinheon Baek | 40 | 3 | 66 Efficient Long Context Language Model Retrieval with Compression (2025) Learned Sparse Retrieval Efficiency 58 Database-Augmented Query Representation for Information Retrieval (2025) Query Reformulation and Expansion |
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| 30 | Xuanhui Wang | 40 | 3 | 65 Accurate language model estimation with document expansion (2005) Query Reformulation and Expansion 57 Can Query Expansion Improve Generalization of Strong Cross-Encoder Rankers? (2024) Query Reformulation and Expansion |
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| 31 | Tetsuya Sakai COI: co-author | 40 | 3 | 58 Flexible Pseudo-Relevance Feedback Using Optimization Tables (2001) Query Reformulation and Expansion 43 ChatRetriever: Adapting Large Language Models for Generalized and Robust Conversational Dense Retrieval (2024) Conversational Search and Retrieval |
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| 32 | Bo Chen 0023 | 39 | 3 | 69 Efficiency Unleashed: Inference Acceleration for LLM-based Recommender Systems with Speculative Decoding (2025) Efficiency and Deployment 40 Generative Representational Learning of Foundation Models for Recommendation (2026) Generative Retrieval and Ranking |
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| 33 | Rolf Jagerman | 39 | 3 | 57 Can Query Expansion Improve Generalization of Strong Cross-Encoder Rankers? (2024) Query Reformulation and Expansion 41 RD-Suite: A Benchmark for Ranking Distillation (2023) Text Embedding and Representation Learning |
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| 34 | Peitian Zhang | 39 | 3 | 66 Hybrid Inverted Index Is a Robust Accelerator for Dense Retrieval (2023) Efficient Retrieval and Indexing 40 Generative Retrieval via Term Set Generation (2024) Generative Retrieval |
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| 35 | Shuaiqiang Wang | 39 | 3 | 45 COLTR: Semi-Supervised Learning to Rank With Co-Training and Over-Parameterization for Web Search (2023) Web-Scale Learning to Rank 45 GS2P: a generative pre-trained learning to rank model with over-parameterization for web-scale search (2024) Web-Scale Learning to Rank |