[Tagging] Layers (was Eruvs etc.)

[Frederik Ramm]

Hi,

On 05.09.22 22:24, Brian M. Sperlongano wrote:
> So if you don't want to see religious boundaries when mapping 
> trees in Karlsruhe, you don't have to - they're separate objects in 
> separate layers that can't be comingled.

I think that this way of thinking ignores an important aspect of OSM, 
and that is the shared responsibility for the whole map.

It is true that a religious boundary is probably not relevant for tree 
mapping, however I do have to take other things into account - for 
example, I could not just switch off the building layer when mapping 
trees because I might then add a tree inside a building which, while not 
strictly impossible, is certainly something that warrants a closer look. 
Or vice versa, a building mapper should not switch off the tree layer 
for the same reason. Or the roads layer, or the waterway layer, etc.

Already, within the boundaries "layer" there are tons of situations 
where it at least superficially appears as if one mapper has in their 
mind "switched off" some layers. For a random example, see: 
https://www.openstreetmap.org/relation/11687912#map=19/49.00522/-122.76048 
- is it really correct that the protected area in the South overlaps 
with the Indian Reserve in the North? Or is this a case of "layer 
thinking" where the mapper of one "layer" did not care how their data 
interacts with other objects?

How likely is it that this parish boundary 
https://www.openstreetmap.org/relation/6854296#map=18/46.84503/-71.22405 
is just *slightly* at odds with the civil administrative boundary that 
runs along the same course 
https://www.openstreetmap.org/relation/8382360#map=18/46.84503/-71.22405 
- or, again, just "layer thinking" a.k.a "I don't care what other stuff 
is in the map, I want to add MY stuff"?

(I have several thousand such "boundaries slightly overlapping but not 
quite" examples all over the planet. A few of them will probably be 
"unlikely but correct", but most will just be sloppy mapping or sloppy 
importing.)

In my opinion, "layer thinking" means giving up on the shared 
stewardship of the map, and allows everyone to dump their garbage into 
OSM with an excuse of "you can switch that layer off if you do not like 
it". I think it would be detrimental to OSM.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"