<div dir="ltr"><div>> Well, as noted above, we won't be consistent, with manual mapping being<br>> done both ways.<br></div><div><br></div><div>That's correct from the stats. And from the wiki, which shows it's okay to add addresses to the elements nodes and areas</div>
<div><a href="http://wiki.openstreetmap.org/wiki/Key:addr:housenumber">http://wiki.openstreetmap.org/wiki/Key:addr:housenumber</a><br></div><a href="http://wiki.openstreetmap.org/wiki/Addresses">http://wiki.openstreetmap.org/wiki/Addresses</a><br>
<div class="gmail_extra"><br></div><div class="gmail_extra">This means the decision process 'to merge or not to merge' can be exercised by the local community. </div><div class="gmail_extra"><br></div><div class="gmail_extra">
Cheers, Johan</div><div class="gmail_extra"><br></div><div class="gmail_extra">ps I am however quite interested in the considerations the NYC community uses for this decision, please share them<br><br><div class="gmail_quote">
2013/10/17 Paul Norman <span dir="ltr"><<a href="mailto:penorman@mac.com" target="_blank">penorman@mac.com</a>></span><br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
I've been sitting on this message, running some stats, but here it is<br>
<br>
> From: Alex Barth [mailto:<a href="mailto:alex@mapbox.com">alex@mapbox.com</a>]<br>
> Sent: Monday, October 14, 2013 9:35 AM<br>
> To: Imports OpenStreetMap.org<br>
> Subject: [Imports] NYC building + address import - to merge or not to merge?<br>
><br>
> Now there's reason to revisit this decision: the data steward (Colin<br>
> Reilly from NYC GIS) told me that NYC GIS took great care to place<br>
> addresses at about where the entrance of the building sits.<br>
<br>
A review of the data shows that this may be true for some buildings and<br>
addresses but is not true for others. As an example, see<br>
<a href="http://pnorman.dev.openstreetmap.org/imports/review/ny_buildings/positions.png" target="_blank">http://pnorman.dev.openstreetmap.org/imports/review/ny_buildings/positions.png</a>.<br>
Some points are near addresses, some are near centroids, and some of<br>
them are strangely at the back.<br>
<br>
> Here is a comparison of the two options. I'd like to discuss and<br>
> decide at tonight's imports hangout.<br>
<br>
Note: Alex, Serge and myself discussed the import at length tonight.<br>
<br>
> ## Option 1: Merge addresses into buildings where possible<br>
><br>
> ## Option 2: Always keep address points separate<br>
<br>
There is some repetition in the two sections, so I'm just going to extract and rearrange points. See <a href="http://lists.osm.org/pipermail/imports/2013-October/002275.html" target="_blank">http://lists.osm.org/pipermail/imports/2013-October/002275.html</a> for the original text<br>
<br>
> a) [points] is the NYC GIS way, making it nicer for GIS folks to use OSM<br>
<br>
GIS folks will have to deal with both so this doesn't really give either<br>
method an advantage. There *will* be addresses on ways that they will<br>
have to deal with. Additionally NYC is only part of OSM, so they have to<br>
deal with practices elsewhere anyways.<br>
<br>
> a) we lose data [when merging points to buildings]<br>
<br>
I'd say the information lost is not significant, given that in many<br>
buildings the point is just the centroid or a random point within the<br>
building. It's not consistent enough to rely on for anything, as you've<br>
stated:<br>
<br>
> Note: it has been suggested to use the address location information to<br>
> tag an entrance. Unfortunately the data is not consistent enough to do<br>
> this.<br>
<br>
> b) Not regarding standing practice, merging addresses into buildings<br>
> is an exception from the generally applicable method of doing separate<br>
> address points.<br>
> b) [merging] makes it harder for NYC GIS to leverage OSM<br>
<br>
How so? Keep in mind that NYC GIS will have to deal with<br>
<br>
- Addresses collected manually without any import tags<br>
<br>
- Addresses on building ways<br>
<br>
- Addresses on building ways where neither the address or building way<br>
comes from an import<br>
<br>
- Addresses on building ways where OSM has split up a structure<br>
differently than they have<br>
<br>
For consumers other than NYC GIS, they'll be in the same position of<br>
multiple styles of mapping.<br>
<br>
> a) [Addresses on nodes inside buildings] diverges (but does not<br>
violate) common OSM practice<br>
> a) [Addresses on ways] is how a lot of buildings are done in OSM<br>
<br>
Unfortunately statistics are distorted by imports, but I had a look at similar practices with merging and POIs with name=McDonald's.<br>
<br>
Of the 5523 locations which could be merged to building polygons, 3315, or 60% were. There were another 5205 locations which were unable to be merged onto a building, either because there were multiple POIs within the building, or there was no building mapped. The actual percentage may be higher as this I can imagine scenarios where the mapper knew there was another POI in the building but it wasn't mapped.<br>
<br>
Results for 80% for name=Walmart and 60% for name=Safeway.<br>
<br>
> Note right now we've imported data in both formats :p I'm not worried<br>
> about this and I'll commit to make sure in the end we're consistent.<br>
<br>
Well, as noted above, we won't be consistent, with manual mapping being<br>
done both ways.<br>
<br>
<br>
_______________________________________________<br>
Imports mailing list<br>
<a href="mailto:Imports@openstreetmap.org">Imports@openstreetmap.org</a><br>
<a href="https://lists.openstreetmap.org/listinfo/imports" target="_blank">https://lists.openstreetmap.org/listinfo/imports</a><br>
</blockquote></div><br></div></div>