[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 


the same river as






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:


which a map producer might want to label the Amazon Rain Forest.

Or these two:


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.



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

More information about the Tagging mailing list