Does the main OSM rendering understand building=university?
On Fri, 22 May 2015 at 12:27 Dan S <danstowell+...@gmail.com> wrote: > Hi David, > > Thanks for the detailed info. My main concern is in terms of the > consequences for other data consumers. If someone tries to use OSM > data for anything - such as: > (a) to plot the density of universities per county > (b) to render a map using a UK-wide rendering scheme that indicates > each university prominently > - the results will be utterly wrong. So we do need some consistency, > at least at the country-wide level. (I'm pragmatic enough not to aim > for global consistency ;) > > So I'm not offended, but I do care that our data is good for everyone. > I suggest that we should make a change but I will not rush anything! > > I don't know what this "camp" is that didn't like building=university. > Was it an OSM camp (eg a discussion on the tagging email list)? Either > way, building=university is now used quite a lot worldwide > http://taginfo.openstreetmap.org/tags/building=university#map - I > think it's pretty uncontroversial as a building tag. > > So the question, I guess, is what "jobs" amenity=university is doing > in your scheme. Is it being used as a selector for extracting data? Is > it being used as a selector for rendering-rules? You've got your > operator=* tagging which looks good for selecting a data extract. > > If we made a two-step change such that all "building=yes, > amenity=university, operator=.*University of Cambridge.*" were first > modified to building=university, and then after a few months to remove > the amenity=university from buildings and leave it on > sites/universities/whatever-we-agree-it-should-be-on - would that work > for you? My quick overpass check suggests that would address about 800 > of the 1200 objects. > > Best > Dan > > > 2015-05-22 11:54 GMT+01:00 David Earl <da...@frankieandshadow.com>: > > Hi Dan, > > > > Yes, Philip's right - I developed and continue to maintain the University > > map at http://map.cam.ac.uk (as well as doing all of the original street > > pattern mapping for Cambridge back in 2006). The University has put a > > considerable investment and negotiated permission for college access into > > the map and contributed tens of thousands of pounds of survey data into > OSM > > - it's not just "some of its maps", it's completely central to the > > University map, not just a casual effort. > > > > The "schema" for tags that make the University map work is at > > http://wiki.openstreetmap.org/wiki/Cambridge/University_of_Cambridge > (I've > > just realised I haven't updated that page with a recent, unrelated new > bit, > > I must do so). > > > > As it happens, I was also thinking about this the other day. The three > main > > things are that is (a) consistent and (b) doesn't change under our feet > and > > break the map, (c) it needs a way to distinguish these buildings from > > others. It possibly wasn't the best decision to do it like this, though I > > still don't think it is a terrible way to do it. Relations would be > awful: > > they are very hard to maintain accurately, and incidentally they are > hard to > > work with in consumers because they come at the end of the data so you > have > > to do multiple passes or keep lots of data in memory, and I think you'd > lose > > most of the distinctive renderings off the OSM map, though since that's > such > > an opaque process it's hard to know. > > > > building=university would work, but only if done in a controlled way so > that > > we don't break the map while it's being done. But do you really want to > > spend your days in front of a computer changing all the university tags > in > > Cambridge though?! I can think of more productive and helpful things to > do. > > I did consider building=university, but like all things OSM, there was a > > camp that only wanted building=yes, and that is what the Map_features > page > > then decreed (it has more now, but university isn't among them). The more > > critical tags from my point of view are the operator ones. > > > > This raises some other points though... > > > > 1. What about the sites and the colleges? These are also tagged > University, > > and there isn't an obvious alternative that won't mean the ordinary OSM > maps > > don't show them. Fundamentally, is a "part of a university" a > university? I > > think it's helpful to do it like that. Did you know the University of > > Nottingham has a branch in China - would it really be helpful to link > these > > with relations spanning the world? I think there's cases both ways. > > > > 2. What is a University anyway? Almost no university is in one physical > > area. Even campus universities like UEA have outlying premises (in UEA's > > case in London too). Do you really not want the campus area to be tagged > > university just because it isn't the whole thing? You said Anglia Ruskin > was > > one of the two universities in Cambridge - no it isn't, it's HALF a > > university, the rest is in Chelmsford. I don't think it would do any harm > > and would be helpful to group them with relations, if that were > maintainable > > sustainably, but not at the expense of losing the tags from the outline > > itself. And the building thing only extends this further. Is a > University a > > geographical thing at all? It's an institution, which may have some > > buildings but really it's a concept not a physical object - ultimately > > everything on the map is just a part, not the whole. > > > > 4. Constantly changing tags creates a moving target that is extremely > hard > > to maintain for data consumers, and is a major off-putting factor in > using > > OSM, especially if you can't manage the process because things just > change > > under your feet. For example, there is a thread on talk discussing > > completely changing the amenities altogether, without regard for people > who > > want to use this stuff in the real world. My view is that tags are merely > > tokens and too much is read into the words. They are part of the API and > the > > fact you can change them because you prefer some other structure doesn't > > mean you should. The flexibility means we can introduce new things > easily, > > but constant change is hard to cope with. The costs are borne elsewhere, > and > > what really does it buy us? > > > > So, I think it's OK the way it is. If it offends you unbearably, > > building=university wouldn't be too hard to cope with, but please, please > > don't just do it, let me change the University software first, otherwise > the > > map will be broken on next update (which are frequent) and they will be > very > > annoyed. As I said, this is effectively part of the API, even though it > may > > not feel like it, and constitutes a non-upward compatible change. If you > do > > want to do it, please do it all, not in bits, and bear in mind this has a > > direct financial cost to me as a freelancer supporting the University > map, > > and that the University has been a big benefactor for OSM, even though > they > > get the rest of the map back in return, so you really don't want to give > > them a slap in the face for doing so. > > > > David > > > > > > On Thu, 21 May 2015 at 23:13 Phillip Barnett < > phillip.p.barn...@gmail.com> > > wrote: > >> > >> I'm a Cambridge mapper, but I'd advise doing nothing until you've spoken > >> with David Earl who was contracted by Cambridge University to actually > map > >> the university - see this link > >> http://soc2012.soc.org.uk/node/16.html > >> Thanks > >> > >> > >> > >> > On 21 May 2015, at 22:39, Dan S <danstowell+...@gmail.com> wrote: > >> > > >> > Hi all, > >> > > >> > I don't relish bringing this up since it's a bit of a tangle, but I > >> > noticed Cambridge has a lot more universities than I thought! > >> > Apparently 1219, judging from the number of amenity=university tagged > >> > objects. In real life I'm aware of two: Cambridge Uni, Anglia Ruskin > >> > Uni. > >> > > >> > I think someone mentioned Cambridge Uni was using OpenStreetMap for > >> > some of its maps,* so I'd be nervous about proposing anything radical > >> > right now. But is there anyone on this list who is a Cambridge mapper, > >> > or connected to the university's use of mapping? It's possible that > >> > some team decided to use the tag to mark every college building (etc), > >> > when really amenity=university is supposed to mark a university, not a > >> > piece of a university. > >> > > >> > To do it "properly" it might need some neat relations to group these > >> > things. (Might be fun for someone who loves relations - various > >> > multi-site and hierarchical connections among the buildings scattered > >> > across town!) Alternatively there are tags in use such as > >> > building=university which might be good drop-in replacements... > >> > > >> > Best > >> > Dan > >> > > >> > > >> > * They use OSM for their basemap: http://map.cam.ac.uk/ - I wonder if > >> > they're getting their POI info from it too > >> > > >> > _______________________________________________ > >> > Talk-GB mailing list > >> > Talk-GB@openstreetmap.org > >> > https://lists.openstreetmap.org/listinfo/talk-gb > >> > >> _______________________________________________ > >> Talk-GB mailing list > >> Talk-GB@openstreetmap.org > >> https://lists.openstreetmap.org/listinfo/talk-gb >
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