[HOT] Buildings in Chad

[Bjoern Hassler]

Hi John,

At the recent Cambridge mapathon, we used this tool
https://github.com/OSM-Utilities/JOSM-Scripts-HOT/tree/master/www
(which we developed especially for mapathons).

You enter the hastags and time of your mapathon, and it produces a list of
changes made by those users during the mapathon, that is "validated"
against certain criteria, e.g. whether 4-node buildings are square, whether
there are untagged isolated nodes, etc. The tool gives you a percentage:

- User ABC: Non-square buildings 2%
...
- User DEF: Non-square buildings 95%
...

So it means that during the mapathon, you can see who just makes occasional
slips vs. systematic mistakes.

At the Cambridge mapathon we used this quite successfully, seeing which
users were putting in a lot of buildings that were not squared (~ 100s of
buildings in two cases). We managed to find them (which of course is not
necessarily trivial), and they corrected the issue before the mapathon was
over. This fixes both the buildings they added (one-off as it were), but
also means they will square buildings in future.

Another use of the tool is to identify where a particular mapathon as a
whole generates lots of non-square buildings, in which case the supporters
need a bit of additional support :) Also, you can tell who doesn't map much
during the mapathon: They might need a bit more encouragement, to make sure
they don't get frustrated, and to make sure they come back.

Even though I say this myself, I think the tool has great promise, and we
demo'd this at the last London mid-month mapathon, so some people will have
seen it. We're also doing a webinar on this later this month. The tool is
really just mashup of the RedCross hashtag API and overpass, but I haven't
seen any other tools working like this. (E.g. in osmcha, you can see issues
with changesets, which is great, but afaik it doesn't allow me to see
whether users are make occasional slips, vs. systematic errors.)

Unfortunately the RedCross api server does not support (see https:
https://github.com/AmericanRedCross/osm-stats/issues/47). Thus we cannot
have an online version, but you need to pull the repo and run locally.
Hopefully this will come very soon.

The 2nd issue is that it can be hard to find users. I wished that the tasks
manager had a way to register users who are doing a mapathon, i.e. as you
start, you put a table number in, which means helpers can find you on the
basis of your OSM id.

For your use case, it would be possible to get the script to produce a list
of non-square buildings, which could then load loaded into JOSM, and cycled
through with the TODO plugin...

Also, any support in our dev efforts is really welcome, including ideas
whether the tool could be integrated into an existing tool...

Bjoern

On 15 July 2017 at 13:10, john whelan <jwhelan0112 at gmail.com> wrote:

> I think they need visually inspecting unfortunately.  They can be done in
> batches ie look for untagged, then select a mapper, then zoom in to a
> settlement so sometimes you can clear thirty at once but I can't think how
> you'd script that.
>
> It's just a little frustrating that some mappers have mapped so much
> without being given feedback that somehow they weren't adding tags and
> feedback more than a week or two after the event gives diminishing returns.
>
> I think the big message is if your project is in Chad pull the map in
> again in a couple of weeks time and it should be a lot better.
>
> Cheerio John
>
> On 15 July 2017 at 03:19, Bjoern Hassler <bjohas+mw at gmail.com> wrote:
>
>> Hi John,
>>
>> Let me know if I can do anything scripting-wise.
>>
>> Bjoern
>>
>>
>> On 15 July 2017 at 02:49, john whelan <jwhelan0112 at gmail.com> wrote:
>>
>>> I'm looking at Chad by bringing 10% of the country at a time.  I'm
>>> seeing thousands of untagged ways most of which are buildings, far more
>>> than I would expect.
>>>
>>> If you're running a project in Chad that includes mapping buildings you
>>> may wish to check the map in a week or two as I continue to tag untagged
>>> ways including buildings.
>>>
>>> You may also want to see if you can have someone validate your Chad
>>> projects with JOSM since its much easier to avoid problems by giving
>>> feedback than it is to clean up afterwards.
>>>
>>> Cheerio John
>>>
>>> _______________________________________________
>>> HOT mailing list
>>> HOT at openstreetmap.org
>>> https://lists.openstreetmap.org/listinfo/hot
>>>
>>>
>>
>
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