[OSM-talk] Unmapped areas and map confidence

[Tom Chance]

Ahoy,

I was mulling over this stuff with Robert Scott in a pub last night, along with other worries...

On Mon, 19 Feb 2007 13:48:56 -0000, "David Earl" <david at frankieandshadow.com> wrote:
> These address one of my major concerns when I first joined OSM, that you
> had no idea of whether what you were looking at bore any relation to reality,
> especially if there was some information there. Of course, the map may
> lie, but usually it is simply just not finished, and very often it is known it
> is not finished and is being worked on.
> 
> Obviously nothing is ever "complete", in the sense that detail can always
> be added, but I think if the surfaced, public streets are there with names,
> then it is "complete" for the purposes of this discussion.
> 
> I and presumably RW, both want to say to people looking at the maps we are
> working on "don't trust this area, we know there is more to do here".

This relates to knowing who else is mapping in your area. I worry that somebody might start mapping a part of St Albans but carelessly mis certain roads, make spelling mistakes (I found one yesterday), not get all of the pubs/postboxes/etc. My fastiduous side hates the thought of my wee city being defiled ;-)

Without having a conversation with the person who mapped an area, or going over it again yourself, it's impossible to know.

Currently we have the wiki pages for localities where you can say "I'm mapping this area", but they don't seem very heavily used and I doubt a lot of mappers find them anyway. There used to be emails in RSS feeds, but so far as I understand it that was hammering the server. There is talk of a facility to get in touch with people in your area by querying the API/db, but it doesn't exist yet. At least being able to get in touch will work if there aren't too many people and everyone is helpful in discussing their activity. But with lots of people, or unhelpful people, it still won't be too much help.

Ultimately this is one way in which OSM is very different to other "wiki-like" projects. With a page on Picasso in Wikipedia you can tell what needs doing. That's just not true of maps, and any tags we put in to try and indicate completeness will always be flawed.

The only system I think works well is updating the wiki pages and talking to fellow local mappers, but I don't suppose we can coerce people into doing that.

Regards,
Tom