[Talk-GB] too many universities in Cambridge

David Earl david at frankieandshadow.com
Fri May 22 12:03:50 UTC 2015


Sorry, that wasn't intended to be provocative, it was a serious question.
Irrespective of how it is tagged, how should one show a spread out
institution on a map? If you do ARU with two mortar boards or some such
should Cambridge be 10, one for each site, 41 including the colleges, or
what? One could argue that it's the mapping you cited that's inadequate
because it should collapse them into one when they are sufficiently close
together to not be distinct (like ios does for photo locations on a map for
example*), and that when zoomed in you *do* want them to be shown
separately. In any case neither the current scheme nor a relation scheme
preclude that, they are currently group-able by operator (which is a much
more sustainable way of relating them IMO than relations).

I asked about the building=university rendering because it would be a shame
to lose the university buildings as distinct on the main map, and I have no
control over fixing that. No doubt someone would catch up with it
eventually.

I would have to go back to the code to see what the exact implications of
removing the amenity tags are, it's three years since I wrote it. I am
almost certain that changing building=yes to building=university is
harmless, but if I then have to rely on it, we have to be careful that
university libraries aren't tagged building=library for example as the
information gets lost.

David

* in similar vein one of the developments that's been requested for the
university map is that when you get a search hit where the result blobs are
overlapping they should be merged into one. This is very hard to do, so it
will cost a lot.


On Fri, 22 May 2015 at 12:40 Dan S <danstowell+osm at gmail.com> wrote:

> 2015-05-22 12:33 GMT+01:00 David Earl <david at frankieandshadow.com>:
> >> to render a map using a UK-wide rendering scheme that indicates
> >> each university prominently
> >
> > What *would* you show for Cambridge (or other spread out ones) for this?
> > Where actually *is* the University of Cambridge? What would you show that
> > the current tagging doesn't already achieve?
>
> It doesn't matter what I would do. The UoC tagging is inconsistent
> with the tagging for other universities, in a way that means no-one
> can currently design a UK-wide map render that can handle universities
> properly.
>
> I understand that you don't like this erupting under your feet, but
> I'm afraid that's what happens in wiki-like systems. Please, please be
> happy that I'm a considerate map editor who tries to discuss rather
> than just to edit. We have absolutely no guarantees that a map editor
> who loves consistency but doesn't love communication will not break
> your schema at any moment!
>
> I'd be really grateful if you could comment on my suggestion about
> modifying the building tags.
>
> Best
> Dan
>
>
> > On Fri, 22 May 2015 at 12:30 David Earl <david at frankieandshadow.com>
> wrote:
> >>
> >> 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
> >>> >> >
> >>> >> > _______________________________________________
> >>> >> > Talk-GB mailing list
> >>> >> > Talk-GB at openstreetmap.org
> >>> >> > https://lists.openstreetmap.org/listinfo/talk-gb
> >>> >>
> >>> >> _______________________________________________
> >>> >> Talk-GB mailing list
> >>> >> Talk-GB at openstreetmap.org
> >>> >> https://lists.openstreetmap.org/listinfo/talk-gb
>
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