[HOT] Data quality in Ecuador

john whelan jwhelan0112 at gmail.com
Wed Apr 20 11:57:01 UTC 2016


Whilst I'm writing I should mention that a mixture of metal roofs, slight
over exposure and slight fuzziness means its sometimes hard to precisely
pick out the buildings although I have noticed my 1920 x 1080 monitor in
the basement shows a much better image quality than one of the laptops I
have lying around.

Cheerio John

On 20 April 2016 at 07:44, john whelan <jwhelan0112 at gmail.com> wrote:

> The good news is it’s a lot better than Nepal was.  I think most of that’s
> down to better training guides so well done training.
>
> In Nepal we saw a lot of tiles marked done or validated when there was
> still a lot to do.  So in Ecuador if there are more than two or three
> buildings missing I’ve been invalidating the tile.  In JOSM if you search
> for buildings they highlight and it makes it easier to spot the missing
> ones.  Some tiles have been invalidated three times.  The tiles are still
> being mapped faster than I can validate them even though for the most part
> I’ve been ignoring the JOSM validation warnings.  I’ve been concentrating
> on the pink zones.
>
> I’ve been briefed that it only takes five clicks to map a building in iD,
> the four corners then “s” for square.  I suspect it also needs a tag for
> the area, so say six clicks.  With JOSM building_tool plugin it takes three
> clicks of the mouse, so if you’re mapping for more than an hour allowing
> fifteen minutes to install JOSM and configure it you’ll get more buildings
> out of the mappers.  The only thing I care about is the quality is higher.
>
> I’ve seen less than a hundred area=yes rather than building=yes, this is a
> vast improvement.  Trouble is it takes time to go and inspect them just in
> case it isn’t a building.
>
> I’ve seen maybe a hundred double mapped buildings.  Again because I
> haven’t taken the time go through the crossing building warnings there
> maybe more in there.
>
> I’ve seen one or two mappers map but not tag.  These need going through
> with the todo tool in JOSM to work out the tags which takes time.
>
> A big problem has been highways, not touching or crossing.  Also in Africa
> we have the wiki for guidance use highway=path rather than footway but I’m
> unaware of anything for Ecuador.  My suggestion would be split the projects
> into buildings and a separate projects for highways.  Highways need a
> higher level of skill or different training.  MSF have used this approach
> successfully.
>
> Squared buildings? What can I say many aren’t.  I’ve also seen several
> hundred mapped as building=house rather than building=yes.  JOSM
> building_tool takes this decision away from mappers.
>
> I haven’t gone over each building.  Sounds an odd thing to say but I’ve
> seen several mappers grouping buildings together and tagging them
> building=yes.
>
> Larger buildings that look industrial often seem to be overlooked.  If
> people were working in there at the time of the earthquake they are of
> interest and looking at damage again I suspect they are of interest.
>
> So thanks to those mappers who have been giving TLC to buildings, I think
> we’re doing reasonably well but if you have JOSM and can recognise a
> missing building please invalidate a few tiles.
>
> Cheerio John
>
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