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United StatesHealthcare and life sciences2017 – ongoing

National Institutes of Health

PubMed Best Match machine-learning search ranking

PubMed's Best Match ranking increased click-through by over 20% in real-world testing

WorkingCompany's own claim

Problem

PubMed's growing biomedical literature collection made relevant papers harder to find. Date-based sorting could place useful older research below newer results.

Approach

National Library of Medicine researchers trained a relevance-ranking model using past searches and document features. Best Match reranked retrieved results with LambdaMART. PubMed deployed it in June 2017 as an alternative to date sorting.

Results

over 20%increase in user click-through rate during real-world testing, reported by NLM researchersCompany's own claim[1]

Takeaway

The evaluation measured search engagement. Higher click-through did not establish better clinical decisions or research outcomes.

Categories

Business function
Production and quality
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 their deployed learning-to-rank system. They reported over 20% higher click-through in testing and millions of searches assisted weekly after deployment.

Full details are in the original sources.

Added 1 Nov 2026 · Updated 1 Nov 2026
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