[Tagging] Colocated school/churchgrounds (was Re: multiple schools on one plot)

[Minh Nguyen]

Vào lúc 06:14 2021-04-10, Jmapb đã viết:
> On 4/9/2021 9:59 PM, Minh Nguyen wrote:
> 
>> To be pedantic, I wouldn't view it as one tag undoing the other, just
>> two completely overlapping tags reflecting completely overlapping land
>> use.
> 
> By "undoing" I was referring to this suggestion you made earlier:
> 
>> That would at least allow a savvy data consumer to differentiate
>> shared school/churchgrounds. For example, an Overpass query would
>> subtract double-tagged amenity=school landuse=religious features from
>> the overall number of amenity=school features.
> If you're asking a data consumer to ignore the amenity=school tag on
> objects that are also tagged landuse=religious, then you're breaking the
> tagging model. Data consumers shouldn't have to check the presence and
> value of other tags to decide whether to trust the first tag.

That's fair. I only pointed it out as a possibility that would be more 
explicit (and thus more reliable) than the current situation, where I 
and others have been using amenity=school twice.

> In the example you've given, if you believe the church is located on the
> school grounds, I don't see any problem with tagging amenity=school on
> the entire area. But then please don't tag an additional amenity=school
> on the school building itself. One school = one amenity.

Someone familiar with the site would consider it to be a schoolground 
and would consider the church to be located on the school _grounds_, but 
not within the school per se. The two amenities are coequal on the 
grounds, even if the grounds has the general character of a schoolground.

I and others have been using amenity=school twice for two distinct 
things -- just like amenity=place_of_worship used to be used for two 
things before landuse=religious became popular [1][2] -- but only 
because there isn't a way to explicitly say that something is just a 
schoolgrounds but not a school. There wasn't ever documentation saying 
that people should use amenity=place_of_worship for the grounds in 
addition to the worship space, but mappers naturally gravitated to that 
double usage because they wanted to express something that they could 
observe.

To be sure, the situation isn't ideal. We both agree that tagging the 
grounds as a landuse of some sort would prevent double-counting of the 
school (because only one definition of amenity=school would be used). 
But I'm pointing out that landuse=religious would overemphasize the 
religious use at the expense of the educational use, while existing data 
consumers already use schoolgrounds for various purposes.

[1] For example: https://www.openstreetmap.org/way/316790070/history
[2] More examples I haven't gotten around to cleaning up: 
https://overpass-turbo.eu/s/15Yx

-- 
minh at nguyen.cincinnati.oh.us