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 <[email protected]>: > 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 <[email protected]> > 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 <[email protected]> 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 >> > [email protected] >> > https://lists.openstreetmap.org/listinfo/talk-gb >> >> _______________________________________________ >> Talk-GB mailing list >> [email protected] >> https://lists.openstreetmap.org/listinfo/talk-gb _______________________________________________ Talk-GB mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk-gb
