Differences between OSM data and MapQuest OSM data?

Question

I currently have an OSM "stack" server (Postgres/PostGIS, Mapnik, OpensLayers) working in a development environment, with almost all the South America countries loaded on the database. Since the applications I'm targeting uses geocoding extensively, I made a test deployment of Nominatim.

While testing, I discovered that almost all searches on Buenos Aires (where my company resides) didn't return a "house number" or something like the "between numbers" of Google Maps. The official Nominatim site didn't return that data neither. But, using the Nominatim service of MapQuest, there is always a house number on the returned XML.

Since MapQuest theoretically use the same data and tools, why they can show that information? Are they using another source of spatial data?

Answer 1

I did:

curl 'http://api.openstreetmap.org/api/0.6/map/?bbox=-58.38,-34.62,-58.37,-34.61'

and saw one entry that had an address and mentioned MapQuest:

<node id="1184735456" lat="-34.6123820" lon="-58.3719110" user="Polyglot" uid="15188" visible="true" version="1" changeset="7448622" timestamp="2011-03-03T19:11:11Z">
<tag k="addr:city" v="Buenos Aires"/>
<tag k="addr:country" v="AR"/>
<tag k="addr:housenumber" v="390"/>
<tag k="addr:street" v="Defensa"/>
<tag k="name" v="Deybel Catering"/>
<tag k="shop" v="catering"/>
<tag k="source" v="mapquest_critical_addresses"/>
</node>

Is this the sort of thing you're seeing? If not, could you provide an example? I'm pretty sure the OSM home page doesn't let you search by street number, though I realize you weren't using that.

Answer 2

Lot of posts says that OSM currently doesn’t have much "house numbers" loaded. Indeed, here in Buenos Aires, a very few streets have house numbers on it.

In OpenStreeMaps.org, if I enter this: "750 lavalle, ciudad autonoma de buenos aires, argentina" ... and click in the first suggested option, the viewer shows the correct street, but the place mark is on the "first number" of the street, probably the first point in the street polyline, ignoring the number, and all different numbers point to the same place mark. If I use Nominating in OSM, all numbers point to the same lat/lon also.

In MapQuest, if I enter the exactly same address, the map shows the correct street, and the place mark is in the correct location of the number 750. I don't know if they are interpolating, but the mark is quite correctly placed. And altering the number, the place mark goes to the correct position too.

If MapQuest uses OSM data, how can MapQuest do that?

Thanks