POI conflation thresholds: why a 2% cross-source match rate is the honest answer
23 June 2026
Two POIs sit 30 m apart with similar names. Same shop, or two shops? Every conflation pipeline answers that question and almost none of them publish the answer.
AnythingPOI, which fuses OpenStreetMap and Overture Maps into 22.7M points across six countries, uses three gates, all of which must hold: 50 m Haversine, agreement on Tier-1 category, and Jaro-Winkler name similarity of 0.85 on normalised names. Candidates are blocked first by H3 at resolution 11, which is the same parameter choice in a different costume. Across six countries the gates match 1.4% to 3.2% of records.
The number looks like failure. Loosening it is trivial: take the gate to 150 m, drop the category check, and the merged count climbs to something that reads well in a table. What you have actually done is fuse the barber and the newsagent that share a parade and a family name, and you cannot tell which of your merges are real.
A cross-source match is worth something in the confidence score precisely because it is rare. It means two independently built datasets agree. Inflate the rate and you destroy the signal that made the field worth adding.
Recall is what this costs. Transliterated names go unmatched, and so does a shopping centre whose centroid sits 200 m from its entrance. That is a deliberate trade, and it belongs in the documentation rather than in a footnote.