[HOT] Squared buildings

Thu Apr 14 21:28:46 UTC 2016

For 95% of the buildings JOSM building_tool plugin does a very nice job
very quickly.  Three clicks and you're done.

The training material for HOT and learnOSM has improved enormously since
Nepal.

I’d probably split the world into three.  Mappers who started in OSM or who
have built up experience in OSM and know where map features is.
Individuals mapping by themselves, they have to read the instructions to
get started.  These I really don’t mind spending the time giving feedback
to, they’re likely to come back and map again.  Then we get the maperthons.

People who organise maperthons and OSM have different objectives.  OSM is
more or less map accurately following the guidelines in map features.  I
say more or less because there is a very wide range of opinion within OSM
on every matter under the sun.

Maperthons group themselves into two groups.  The first is organised often
by a group such as MSF and they have training and handouts plus experienced
mappers around to assist new mappers.  Quite often they get returning
mappers and they can be nudged towards JOSM.  They are concerned both with
mapping, building community (drinking coffee together) and spreading the
word on how wonderful MSF or whomever it is running the show is.  If I
notice problems when validating these not a big deal its comment the mapper
and bug the project manager with a bit of feedback.  Often they’ll have
simplified projects such as just map the highways and nothing else together
with simplified instructions.  If you accept that 60% of the mappers will
only map the once then iD takes less time to get started than installing
JOSM.

The second are much more difficult.  These often run by what I call social
groups of one type or another, short attention spans, real men don’t need
instructions.  If you’re lucky they’ll have a handout, if not well anything
goes and next week we’ll do something entirely different.  If you
invalidate so what, 99% won’t be back.  You’re just left with a mess.  A
group descended on a project I was watching as a validator recently.  I
wanted to contact the organiser as it was obvious they had no training at
all but no one knew who they were.  The project manager certainly didn’t
and that’s where the question comes from how do we handle these situations?

One tile I added ninety two settlements and about fifty highways to a tile
when validating, the second tile by the same mapper just got invalidated
when I saw four large settlements missed at the first glance.  In the
building projects the numbers are much higher.  It’s not unusual to see a
hundred buildings on a tile and many will not be square, I still see quite
a few area=yes rather than building=yes although that is improving.

The other problem is validation.  Mappers who haven’t completed a single
tile validating.  Go in behind them and you see all the unsquared
buildings, crossing highways etc.

Prevention is usually cheaper than remedial work.  I have great hopes for
the iD building plugin, but in the mean time the question remains what to
do about the existing unsquared buildings?

Whilst going in with the JOSM todo list plugin and examining every building
by a particular mapper is the ideal solution given the numbers involved do
we accept select the buildings by a mapper on a tile then hit the square
button?

It is a data quality issue but do we even care if they are unsquared or not?

Cheerio John

On 14 April 2016 at 16:25, Paul Norman <penorman at mac.com> wrote:

> On 4/14/2016 1:16 PM, Mike Thompson wrote:
>
> Those are both things that I already tell new mappers. But they type 's'
> and think they have made a square building.  We can talk about how that
> they should notice that nothing changed, but no one has ever asked me "why
> doesn't the 's' key work?" Perhaps they think that the squaring happens
> behind the scene and isn't visible? Who knows. Below are some of the
> results (blue buildings) from a recent mapathon.
> [image: Inline image 1]
>
>
> They're not attempting to square the buildings, which indicates a problem
> with how they're being instructed. Both iD and JOSM would have squared some
> of them with no problems, so switching editors or other technical solutions
> won't help here.
>
> If all of those buildings have square corners in reality, there's a second
> problem that some are so crudely drawn that neither iD or JOSM will come up
> with a sensible result when attempting to do so.
>
> _______________________________________________
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> HOT at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/hot
>
>
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