2 posts tagged with "Geocoder hubris"

There is a particular kind of engineering misery where you fix a bug three times and it never gets better, because the bug is in your ruler. This is that story.

Our neural parser handles German two ways. Native order — Hauptstraße 5, 10115 Berlin — is the layout real German feeds and real German people use. International order — 5 Hauptstraße, Berlin, 10115 — is the Americanized layout our evaluation set happens to ship. For months, international-order German "collapsed": locality accuracy sat around 44% while native cleared 80%. We had a story for it. The postcode anchor — a side-channel that feeds the model a country hint derived from the postcode — sits at the trailing postcode, which in international order lands on the far side of the locality from where it's needed. Plausible. So we retrained.

Ask a geocoder for "Berlin" and it has to make a choice. There's the one in Germany, obviously. There's also Berlin, New Hampshire (population nine thousand and change), Berlin, Wisconsin, Berlin, Connecticut, and a dozen more scattered across the United States like the name was on sale. The parser hands you the word Berlin tagged as a locality; something downstream has to decide which dot on the map that is. How would you even know if it picked right?

For a long time our answer was a scorecard that checked the name. Did the resolved place's name equal the expected name? Tick. Move on. It is a completely reasonable thing to measure, and it was lying to us for months.