[Talk-GB] too many universities in Cambridge

[David Earl]

Does the main OSM rendering understand building=university?


On Fri, 22 May 2015 at 12:27 Dan S <danstowell+osm at 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 <david at 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.barnett at 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+osm at 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
> >> >
> >> > _______________________________________________
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> >>
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