[Tagging] Stop the large feature madness (was: Tag for a plateau or tableland?)
Christoph Hormann
osm at imagico.de
Thu Apr 18 16:52:06 UTC 2019
On Thursday 18 April 2019, Kevin Kenny wrote:
>
> And therefore the Amazon, the Nile, or the Mississippi ought not to
> be named in such a way that a large-scale map can show the names?
Map producers are obviously free to show labels however they want. They
don't need mappers to hand curate dedicated labeling objects for that.
Ironically the waterway relations we have are not really of much use if
you want to label rivers in a map.
> Essentially, you're making the statement here that if local mappers
> pool their knowledge to realize that the river in Alexandria is the
> same river in Aswan, that's a mere social convention and has no place
> on the map.
How should they determine that based on local knowledge? What if there
is disagreement? Is
https://www.openstreetmap.org/way/83015625
the same river as
https://www.openstreetmap.org/way/4769426
or
https://www.openstreetmap.org/way/174752117
or
https://www.openstreetmap.org/way/234008385
What if the local mappers do not speak the same language? Do those who
speak English automatically get to overrule those who don't?
> > Everything else in physical geography is typically mapped locally
> > piece by piece like the rivers and creating large features - while
> > done by some mappers for the purpose of label painting - is
> > generally disliked by most mappers because it is very hard to work
> > with these and represents no additional meaningful information.
>
> That's where we disagree. The additional information is that the
> multiple features represent the same physical object.
And how do you verifiably determine if two things are part of the same
physical object? For example:
https://www.openstreetmap.org/way/335279145
https://www.openstreetmap.org/way/301691395
which a map producer might want to label the Amazon Rain Forest.
Or these two:
https://www.openstreetmap.org/relation/5567277
https://www.openstreetmap.org/way/470015023
which another map producer might want to label the Eurasian Taiga.
> Please avoid the term "label painting." What you call "label
> painting" is the entirely reasonable desire to have recognized, named
> objects appear on the map with their names.
I distinguish between names and labels. Labels are graphical
representations of names or other strings in map renderings. The OSM
database should not contain labels, it should contain names.
This:
https://www.openstreetmap.org/relation/9359806
is not a named representation of a verifiable element of the geography,
it is a labeling geometry. Creating such is not mapping, it is label
drawing or label painting. It is neither meant nor suited to do
anything other than performing a relatively simple label placement.
Note by speaking of "label painting" i do not intend to assign one sided
blame to mappers for doing so. In most cases this is as much the fault
of map designers encouraging this as it is of mappers to respond to
this incentive.
> The "hard to work with" argument is what I said is a technological
> limitation.
With "hard to work with" i was referring to work for the mapper in
maintanance, editing and also just dealing with the object being in the
way when editing other things. That is not a technological limitation.
When you talked about technological limitations you were referring to
problems of data users.
> Now, I could imagine that if the world were other than as it is,
> another culture might insist that the main stem of the river was the
> Missouri, rather than the upper MIssissippi, leading to disagreement
> about the boundaries. That disagreement could be very ugly if the
> cultures were, say, continually embroiled in political conflict about
> other matters. In that case, making a single decision about the
> boundaries might conceivably be imperialistic.
I am glad you understand the problem. If you now look at examples
outside the United States (where if i may say so the originally
different cultures have been largely "homogenized" a long time ago) you
will realize that the situation is often not that simple in other parts
of the world. The fact that people from more than a hundred countries
from all over the world with very different cultures, world views and
languages in OSM work together in collecting local knowledge despite in
many cases not even being able to verbally communicate with each other
is quite remarkable. But this amazing cross cultural cooperation
hinges on on the local verifiability of those things people map.
Adding large scale concepts to the database that are not verifiable
based on local knowledge means throwing a wrench into the gears of this
amazing machine.
--
Christoph Hormann
http://www.imagico.de/
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