Built independently by an author, for readers. Read the story and support ChapterPal

keyword

document representations

Document representations are structured formats, numerical encodings, or textual surrogates used by information retrieval and natural language processing systems to capture the semantic content, features, or identity of documents. In computational retrieval systems, these representations transform raw, unstructured text into standardized forms—such as dense or sparse vector embeddings, bag-of-words models, semantic identifiers, or associated synthetic queries—suitable for automated indexing and matching. By encoding the underlying meaning or topical focus of a text into an abstracted surrogate form, machine learning models and search algorithms can efficiently store large corpora, evaluate semantic relevance, and rank documents in response to user queries.

1 item

How Does Generative Retrieval Scale to Millions of Passages?

How Does Generative Retrieval Scale to Millions of Passages?

Ronak Pradeep, Kai Hui, Jai Gupta, Ádám D. Lelkes, Honglei Zhuang, Jimmy Lin, Donald Metzler, Vinh Q. Tran

OrganizationsGoogleUniversity of Waterloo

Why you should read this

Presents the first comprehensive empirical evaluation of generative retrieval scaled up to 8.8 million passages and 11 billion parameters, showing that while synthetic queries are vital for indexing, current architectures struggle to match standard dual encoders as corpus size grows.

The emerging paradigm of generative retrieval re-frames the classic information retrieval problem into a sequence-to-sequence modeling task, forgoing external indices and encoding an entire document corpus within a single Transformer. Although many different approaches have been proposed to improve the effectiveness of generative retrieval, they have only been evaluated on document corpora on the order of 100K in size. We conduct the first empirical study of generative retrieval techniques across various corpus scales, ultimately scaling up to the entire MS MARCO passage ranking task with a corpus of 8.8M passages and evaluating model sizes up to 11B parameters. We uncover several findings about scaling generative retrieval to millions of passages; notably, the central importance of using synthetic queries as document representations during indexing, the ineffectiveness of existing proposed architecture modifications when accounting for compute cost, and the limits of naively scaling model parameters with respect to retrieval performance. While we find that generative retrieval is competitive with state-of-the-art dual encoders on small corpora, scaling to millions of passages remains an important and unsolved challenge. We believe these findings will be valuable for the community to clarify the current state of generative retrieval, highlight the unique challenges, and inspire new research directions.

Added

2026-09-26