The way Nominatim assembles addresses. Why include isolated_dwelling?

General talk
1

Hello,
I’m sorry, but I need help understanding why search results in OSM / Nominatim display addresses in cities and towns, very often including names of hamlets, isolated dwellings etc.
Which benefit could be exist, to determine all the isolated dwellings in a town area and simply put the name of nearest one in the address results? Even if searched address is located in middle of settlement / town?
In my view this procedure leads to wrong and unclear address results.
I’d like to suggest to give up processing and outputting names of isolated dwellings within the search procedure. Especially in case of existing (mapped) town areas.

Is anyone else concerned about this? I wonder not to find much of this topic, but for some few conclusions that’s just the way it is.
Glad to get feedback!
Regards, Chris

2

This doesn’t appear to be a question!

See http://wiki.openstreetmap.org/wiki/Nominatim/FAQ for the way that the reverse geocoding is done and how to contact the developers. It would appear that what you need to do is to add is_in tags to to the relevant streets.

As Nominatim is based on administrative boundaries, it is not going to give you the correct postal address if that differs from that implied by its administrative location.

3

Thank You for Your answer and the link.

I don’t mind about correct postal address, but if you search for any POI, street or what ever in a city and the result in all cases contains names of outlying homesteads, i’m bothered by it.

My questions, sort of, are: Is the behavior intentional and/or are there deficits in the way, many places are mapped and tagged, and therefore different mapping required?

Many places are currently mapped like:
city/town:
relation with

  • administrative boundaries as outer
  • single node with “place” tag as label and admin_center

isolated_dwellings (located inside the administrative boundaries):
single node with “place” tag

4

I don’t know where you are located, but in my part of the world you need to include dwellings outside of the official town or city boundaries to have reasonable results.

One issue Nominatim and OpenStreetMap have is covering the whole world when conventions vary so widely from place to place. What makes sense and may be absolutely necessary in some regions are nonsensical in others.

5

That’s a good hint and helps me to clarify the purpose.
It’s about Southern Germany.
Obviously the actual definition of isolated_dwellings doesn’t fit to the cases I found, cause these enclaves aren’t administrative but regulated by land-use planning.
In such cases not to use this “place-tag” or “place-key” at all maybe better. Or there should be added boundaries to the dwellings however.