[HOT] Task manager description/instructions #591
pierzenh at yahoo.fr
Fri Jan 2 19:01:08 UTC 2015
It certainly simplifies to first trace the major roads. We did sometimes trace in priority these roads, then landuse before mapping more in detail. But this is Crisis management and we seldom have time to proceed this way. We sometimes try to have the more experienced mappers to take care of such tasks.
One area were I see that we can make progress controlling the mapping qality is with the Mapathons. There were many Mapathons this fall, either for the Ebola outbreak or for the Missing Maps project. This brings a lot of new contributors learning how to map, making a lot of mistakes that need later to be corrected.
A Mapathon Guide would help to provide tools for the organizers to take care of the quality of the data and exchange with the participants to realize the various mistakes and the good practices (ie. Imagery interpretation, geometry, tags, etc.). This would be also more stimulating for these new contributors and help to keep more of them on the long term.
A tool like http://overpass-api.de/achavi/ could help. Some Overpass queries would also let monitor various layers such as buildings, landuse, roads. This would both show the progress made and highlight what should be corrected.
De : Blake Girardot <bgirardot at gmail.com>
À : john whelan <jwhelan0112 at gmail.com>
Cc : "hot at openstreetmap.org" <hot at openstreetmap.org>
Envoyé le : Vendredi 2 janvier 2015 10h57
Objet : Re: [HOT] Task manager description/instructions #591
On 1/2/2015 3:41 PM, john whelan wrote:
> How can we make the best use of what we have? I wonder if some sort of
> work flow might be better. Pass 1, do the major roads and towns /
> larger villages, Pass 2 rivers, pass 3 tracks, pass 4 forests etc.
> Perhaps rivers should come first?
Yes, this is for sure a good idea. Difficult to do in practice, but a
>Certify the mappers, self
> certification would be fine but a small training course this is how to
> map a road, this is how to map a village, this is how to map a river,
> this is how to map a building (JOSM building tool?).
Again, a very good idea, and the Training WG is considering something
None of the typical mapping tasks are difficult to do, but a little bit
of specific training, like 30 mins worth, can make a huge difference
between something that is mapped and something that is well mapped.
It would really be great if we had a small training programing of some
sort, I think it could all be done on line with text and images. Again,
the Training WG is working on this idea so if anyone is interested in
helping with it please let us (training wg) know.
Or we could run online workshops for an hour or so to do mapping
training. At this point I have done 8 or 9 online training sessions and
they work out pretty well (I think :). I have also been very lucky and
received online training from Andrew Buck and Pierre Béland which was
> At the moment we seem to have a number of different people going over
> the same ground mapping the same things which to me is a waste of
> resources and no real agreement as to when a tile is complete, ie no
> service level agreement. I've even seen a building mapped over a building.
Yes and no about the waste of resources. The system is designed so that
multiple eyes will look at the mapping. The obvious version of that is
the validation process, but even that needs multiple passes to make sure
things are validated correctly.
Project managers can "validate the validations" and experienced mappers,
currently self-selected, can also "validate validations".
But multiple projects over the same area for either updates to imagery
or different mapping focuses (roads, waterways, etc) will lead to
validation of previous validations as well so there is a real benefit to
what seems like a waste of resources.
Just 2 passes over an area (initial mapping + validation) is not enough
to generate the highest quality data possible. In my experience so far a
minimum of 3 passes is needed to be sure you are getting high quality
data and the 2nd and 3rd passes are almost as much work as the first pass.
Project managers or local OSM groups often give the mapping 3rd and 4th
passes to correct and refine the initial mapping data as well.
With a simple and short training program for different types of mapping
things would improve some.
Thanks for the thoughts John.
HOT mailing list
HOT at openstreetmap.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the HOT