A thing I learned about neighborhood names and Nominatim
Posted by brittag on 4 April 2015 in English. Last updated on 13 April 2015.Here’s something I learned today, which might be interesting for other people working on mapping or on improving user experience for map editors.
I recently found that when I searched for Isla Vista Elementary School, its place name listing included “Ellwood” as the neighborhood, which is incorrect - the school is in the neighborhood of Isla Vista (as you can probably guess from the name), not in the nearby Ellwood neighborhood. I wanted to fix this, but I was confused about where this Ellwood place name was coming from - I couldn’t find a tag on the school that mentioned Ellwood, and I couldn’t find a boundary/border/area for Ellwood that included the school. Part of the weirdness to me is that Ellwood is in the city of Goleta, and Isla Vista is in unincorporated county land outside of Goleta.
Then I asked about this on #osm IRC, and a person explained that to figure out what’s going on here, I could look up the school on Nominatim (which I hadn’t heard of before other than seeing a mention of it in the search interface and didn’t know what it was!), which said that Ellwood was a nearby node. Then #osm told me the next thing I needed to know: that Nominatim was probably using the Ellwood node as a guess for the neighborhood since it didn’t have anything better, such as a closer node or an area.
Ah ha! So I put in a neighborhood node at the center of Isla Vista with the name “Isla Vista”. Now if you search for Isla Vista Elementary School, the generated address includes “Isla Vista” in the place name listing. It now also includes “El Encanto Heights” though, since that’s another nearby neighborhood node - which is incorrect as a place name for the school’s area. So it looks like I’ll need to figure out how to put in an area boundary for Isla Vista if I want this to be more reliably accurate.