[OSM-talk] Visually detect missing roads

[SomeoneElse]

On 15/09/2014 08:53, Stephan Knauss wrote:
>
> So actually a map with no diff is good. At least a good indication 
> that the map is not missing something important. Assuming for a moment 
> that Google data is a perfect reference (which is not as we all know).

Unfortunately, "we" (as in all OSM users using QA sites) don't all know 
this.  That's why I made the comment up the thread about Google (and 
actually also Apple) Maps showing a road locally to me that doesn't exist.

There's an increasing problem with relatively inexperienced users* 
thinking that if a QA site no longer shows a problem, then the problem 
is "fixed", and here it's compounded by saying "a perfect map is grey".  
In reality of course you'd need to go there and have a look to make 
sure.  Of course, sometimes you can't do that (the area's physically 
inaccessible, or far away and there are no local mappers available to 
fix a problem) and in those cases QA sites such as yours can be 
extremely useful.

Other QA sites tend to make it clear what they're actually showing (e.g. 
"musical chairs" has in capital letters at the bottom of the screen 
"THIS IS A LIST OF DISAGREEMENTS, NOT NECESSARILY OSM ERRORS".  Clearly 
some sort of disclaimer text like that would make sense, but would it 
perhaps also be possible to guide new mappers towards other fixing 
options available, such as:

o find a local mapper and contact them - even just to ask if (a) is 
correct and then (b), and then do the edit based on that.

o where there are no local active mappers add a note that someone can 
see when they're next in the area requesting a survey.

Cheers,

Andy

* actually, it's not just relatively inexperienced mappers. Recently in 
the UK we had someone inventing footpaths to join (arguably mistagged) 
highway=pedestrian islands to nearby roads. Just this morning we've had 
someone decided that the actual metal signs describing a road are 
clearly wrong when compared to what Ordnance Survey's open data says.