Hi John,

 

I have no formal role in HOT, just a casual OSM mapper so all these comments 
are from that perspective. I have participated in HOT projects via their 
tasking manager. I am also not a coder but am aware of the process involved in 
respect of the ID Editor and Tasking Manager development.

 

I don't think building issues are restricted to HOT projects. Indeed when I 
first started mapping in my own neighbourhood I didnt really have a clue on how 
to map buildings but over time I found videos, joined mailing lists, found 
LearnOSM, found tasking managers across the globe and generally became a better 
mapper. At each step I learnt more and hopefully became a better mapper. I 
still don't do any validation as I don't consider myself experienced enough in 
JOSM and lots of the other validation tools. I have participated in some map 
roulette challenges.

 

As you have indicated in previous emails, a building tool in ID may stop some 
of the issues you mention and from my investigation this is actually underway 
already (and has been for some time). Any assistance you can provide would be 
appreciated by everyone involved.

 

I will try and answer specific points in your email from my personal 
perspective.

 

·         I think all buildings should be polygons rather than points. Better 
to teach people how to map as polygons rather than expect another mapper to 
replace a point with a polygon at some time in the future (if ever).

·         Incorrectly mapped building - I would always try and correct the 
error if I had the required skills. If there were many on the tile in a tasking 
manager project that were poorly mapped I suspect I would invalidate the tile 
if I could not fix them. I would also expect some details from the validator, 
maybe with guidance on where good instructions are for splitting the building 
and maintaining any past history on the object.

·         Likewise for buildings 50% greater than actual - I would do the same 
as above - guide the mapper on what they have done wrong and lead them to 
better resources.

·         Buildings mapped twice. I am on a crappy Australian fibre to the node 
connection that regularly crashes so I save regularly (20 - 30 objects). I dont 
quite understand your comment that a four hour tile lock limit would eliminate 
this problem - seems completely wrong to me. I would certainly be saving more 
frequently than every 4 hours. Maybe a reminder popup, after 100 objects, might 
be a better solution to ensure folks are regularly saving.

·         I don't agree with the view of HOT that "We are the professionals and 
we know best". Having lurked on the HOT slack channels I have seen how they 
size up disasters, deal with local OSM groups and other disaster relief 
organisations before embarking on projects. Indeed on a few occasions they have 
not undertaken any projects when the local communities have indicated they have 
the situation in hand. In those cases they simply offer support if required or 
use their communication channels to direct mappers to the other task managers 
(if desired). There are regular references to local OSM groups prior to project 
commencement.

·         As for what is acceptable mapping for a building. The best we can 
hope for is improving tools, educating mappers, more validation tools plus 
willing volunteers (or dare I say it, paid workers) to keep an eye on things 
and help the community make OSM an always improving product.

 

Volunteer gathered information is a bit of a dark art at the best of times and 
many folks/governments are still coming to grips with how it all works and how 
beneficial it can be. Is it perfect...not really, can it be improved...always. 
I think the HOT (and other) tasking managers and the ID editor are always 
improving with better task details, more links to resources etc. I think it's 
up to all of us to contribute in any way we can and put forward ideas, time, 
funds or expertise to make things better.

 

I wasn't aware of the OSMF mailing list so I will join that as well and read up 
what has been happening.

 

Cheers - Phil

 

 

From: john whelan [mailto:jwhelan0...@gmail.com] 
Sent: Sunday, December 10, 2017 7:00 AM
To: hot@openstreetmap.org
Subject: [HOT] Buildings and HOT's reputation in OSM

 

Recently there has been some discussion of HOT's input into OpenStreetMap in 
the OSMF mailing list.

 

Perhaps one of the problem areas is mapping that is less than ideal.

 

Basically HOT mainly maps highways, landuse=residential and buildings.

 

These shouldn't be difficult to map correctly.

 

Buildings appear to be the most problematic.

 

I think we need to think about why we are mapping them.  Is node good enough?  
There would be less room for mistakes.

 

If we need outlines and there good reasons why an outline is more valuable than 
a node then we need to define what is acceptable.  Or do we even care?  and its 
the do we even care part that is perceived to be the case by some within OSM 
and that perception is something we should care about.

 

>From a validation point of view does it matter if the building is not square?  
>Is it acceptable to square a building even though we know this will introduce 
>an element of approximation or error.

 

What should be done with a building=yes that covers more than one building?  Do 
we expect the validator to map each building or just invalidate the tile?

 

What should be done when the building mapped is more than 50% larger than the 
image?  Invalidate the tile?

 

We are still mapping buildings twice.  I suspect some mappers are not uploading 
within two hours.  Getting mappers to upload every 30 minutes max would go a 
long way to reduce this, extending the tile lock to four hours would almost 
certainly eliminate it.  Recently on high priority project I've seen in the 
order of a hundred buildings double mapped.  They have been done within the 
last two weeks so it is an ongoing problem. There is a new tool that detects 
these so they aren't the problem they once were but someone has to run the tool.

 

If HOT could support a few more projects that were from the community on the 
ground rather than the "We are the professionals we know what is best" which 
appears to be perceived sometimes from the number of projects for the RED Cross 
or other northern hemisphere charities that might also help the reputation and 
relationship. 

 

So two points here on one message first is can HOT's reputation be repaired and 
I suspect that is longer term problem that will take time and a lot of effort 
rather than a PR job.

 

Second would someone care to comment on what is acceptable mapping for a 
building and what guidelines can we give to validators? 

 

Thanks John

 

 

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