[OSM-talk] Nominatim QA

[Sarah Hoffmann]

Hi,

On Mon, Jan 10, 2022 at 05:18:12PM -0800, Clifford Snow wrote:
> I just discovered Nominatim Quality Assurance https://nominatim.org/qa Wow
> - it's great. Thank you for adding this tool. It's really helping as I
> prepare for doing a building and address import. Using this tool will help
> insure the quality of the import. Please note - I haven't even started on
> writing up the import. That will wait until I'm satisfied with the quality
> of existing addresses and street names.

I'm happy to hear that you find the tool useful.

Regarding address imports, I've noticed that while they are generally of
a quite high quality, they still tend to forget to about consistency of
data with respect to street names and the addr:street tag. The US are
especially hard hit by the problem because Tiger data as used in street
names and county GISes as used in addresses tend to follow slightly
different spelling conventions and apply directional prefixes
differently. It is very easy to spot the address imports here:
https://nominatim.org/qa/#map=5.25/39.58/-98.91&layer=addr_street_wrong_name

These discrepancies are not the end of the world but they do have an
impact on the overall quality. Not all of the are easy to work around
for a geocoder and so sometimes lead to real errors in the database.

So maybe you can keep an eye on that when preparing your import.

> Does anyone know the refresh interval for the QA tool?

Updates run once per day with new ones being available usually around
4am UTC. We are working on showing the date in the UI.

Sarah