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United StatesPublic sector2017 – ongoing

National Library of Medicine

PubMed Best Match machine-learning search ranking

PubMed reported 60% growth in relevance-sorted searches after deploying Best Match

WorkingCompany's own claim

Problem

Rapid growth in biomedical literature made relevant papers harder to find. PubMed needed a stronger alternative to sorting results by publication date.

Approach

NLM's National Center for Biotechnology Information deployed Best Match in June 2017. It trained the ranking model on past searches and article-level relevance signals. The system reranked an initial set of search results using LambdaMART.

Results

60%increase in relevance-sorted PubMed searches after deployment, reported by NLM researchersCompany's own claim[1]
over 20%increase in user click-through rate in real-world testing, reported by NLM researchersCompany's own claim[1]

Takeaway

The reported growth measured use of relevance sorting. Separate testing measured whether users clicked results.

Categories

Business function
IT and R&D
Evidence
Company's own claim

Sources

  1. Best Match: New relevance search for PubMed
    PLOS Biology28 Aug 2018Research paper or report

Source summaries

[1]PLOS Biology28 Aug 2018

NLM researchers described the ranking system and its June 2017 deployment. They reported 60% growth in relevance-sorted searches and over 20% higher click-through in real-world testing.

Full details are in the original sources.

Added 1 Nov 2026 · Updated 1 Nov 2026
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