jwhelan0112 at gmail.com
Fri Mar 27 12:09:11 UTC 2015
> Hello, I read your message about validating, I am new, I have digitized
a lot of buildings for Malawi, and the Vanatu. I thought I should just jump
in, work as completely as possible and then leave it to be validated. I
don't feel confident enough to say its done. Is that the wrong way to go
about, I don't want to generate a backlog for anyone. Thanks Keith
I'll reply in the general message area because it maybe of interest to
First any mapping you do will be of use and will be used.
There are a couple of issues, first is OSM has many different opinions and
these are just mine.
HOT is more structured than OSM so we have a process where an area is
defined, a tile and only one mapper works there at a time. Ideally the
tiles are the right size so one experienced mapper who knows what they are
doing can complete a tile and mark it done in a session. Then someone
validates it. Sometimes this is done in a maperthon where experienced
mappers are available to assist. Sometimes its done by people working by
Reality at the moment is we have a lot of inexperienced mappers and even
with the experienced ones they have different ideas about what should be
tagged and how they should be tagged. Some work is being done about
getting guidelines drawn up with examples to assist. Ideally with new
mappers you want to validate and give feedback fairly quickly. It reduces
the number of errors in future and giving some sort of feedback is
generally motivating but we do have tiles that haven't been validated in
On Project 917 I aim to validate within one day and often within a few
hours. I am not the project manager for 917 by the way. If you look
you'll see quite a few tiles that haven't been validated. I marked them
done so by convention someone else needs to validate them.
Generally speaking if you break a complex task down then you can divide it
up between less experienced people and leave the complex bits to others.
This is normal production line work flow. We are dealing with volunteers
so the more boring jobs just don't get done and we have a lot of boring
jobs to do.
For urgent tasks we can swamp them with mappers. For less urgent tasks it
becomes more complex how do we deliver as much as we can that is usable to
the client, in this case the NGOs, given the very limited resources we
have. Mapping buildings is nice for the NGOs but given the choice between
one village complete with all the buildings and twenty or thirty mapped in
outlines complete with connecting roads which would you prefer and that's
part of the reason many newer projects do not ask for buildings. The other
part is ones that do often don't get completed. Projects 684-689 are ones
that ask for buildings. Ebola related but its been some time since any
mapping was done. If you don't mind doing a few buildings by the way 684
It takes time to go over a tile so if more than one mapper works there we
are burning up resources as each one scans the tile. If we simplify the
tasks so that one less experienced mapper can go in and map the settlements
and connecting roads then mark it done this is good. Validate it quickly
and move on.
When we add complications such as mines, schools, farmland, and ask mappers
to tag the road according to the width then the less experienced mappers
feel less confident about marking something done. "If you can drive a 4X4
down it its a track", well yes but you'd be amazed where I can drive a 4X4
and some hazards for a 4X4 are not visible from a satellite image. At that
point we are probably spending more people time going over the same tile
than we could be and the tasks are still not being marked done. On 917 by
the way I typically add in anything missing when validating so that can be
a dozen settlements etc so just mark it done when you think its more or
less complete and I'll sort it out but you need to know the validators on
your project before you can tackle tiles this way. Oh you'll probably get
a message saying the little round things in clusters are huts in
settlements by the way.
So my comments on validation are aimed not so much at the urgent tasks
where we can pull a rabbit out of a hat but more at how can we get more
maps for the clients out the existing mappers and how do we keep the
mappers we do have motivated?
Does that make sense?
On 27 March 2015 at 02:34, Esther Zurcher <zhamm at att.net> wrote:
> Hello, I read your message about validating, I am new, I have digitized a
> lot of buildings for Malawi, and the Vanatu. I thought I should just jump
> in, work as completely as possible and then leave it to be validated. I
> don't feel confident enough to say its done. Is that the wrong way to go
> about, I don't want to generate a backlog for anyone. Thanks Keith
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the HOT