[Talk-GB] too many universities in Cambridge

Dan S danstowell+osm at gmail.com
Fri May 22 11:34:07 UTC 2015


I don't think it renders it (though I thought it used to).

The humanitarian style renders the tag, and Cambridge looks mortar-board crazy:
http://www.openstreetmap.org/#map=15/52.2039/0.1182&layers=H

Dan


2015-05-22 12:30 GMT+01:00 David Earl <david at frankieandshadow.com>:
> 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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