[OSM-talk] Help with way forward with Grab
mishari at mishari.net
Mon Jan 7 14:23:18 UTC 2019
Some people from the Thai mapping community are meeting Ajay, the mapping
lead from Grab to discuss the quality issues we've been having with their
mappers but before we do this I wanted input from the wider community. For
those who are unaware, Grab has commissioned another entity, Global Logic,
to do the edits.
I've made some example of quality issues here:
https://wiki.openstreetmap.org/wiki/Grab/Issues I think I need more help to
categorize the problems and propose remedies for them especially in the
context of directed mapping teams. There were also more issues documented
in this thread https://forum.openstreetmap.org/viewtopic.php?id=6407 but I
haven't sorted through all of them. This process would at least take the
focus away from individual problems and allow us to come up with a strategy
for dealing with classes of problem instead.
>From what I can tell, these are the broad classes of issues:
1. Connecting roads where no connection exists - ie. making guesses where
there are buildings or tree covers blocking satellite imagery.
2. Incorrect Tagging - i.e. residential roads in areas marked as parks
3. Not using up to date satellite imagery and overriding recent changes
made by local mappers
4. Changing existing tags - ie. secondary_link to primary etc. overriding
local mappers discretion.
5. Micro-alignment using satellite imagery
What I would like help with is this:
1. What's a fair expectation from such a mapping team? On one hand there's
the potential to add much geometry to the project, on the other hand any
bad data has an outsized effect on utility and perceived quality. What's
the sweet spot? Sadly Bicycle routing in the Grab mapped areas in Bangkok
using Brouter.de is now unreliable because service roads have been added
without information about access permission or barrier and in other cases
ways have been connected where no connection exists.
2. Thailand's mapping community is small and it would be impossible for us
to go through all 7,000 edits made and set it right. I've identified at
least one of the issues (1-3) in roughly 1 out of 4 changesets made by
Grab/Global Logic in my neighborhood in Central Bangkok and I would be
unable to give feedback on any issues outside of this zone, likely the same
with other mappers.
2.1 Should we just ignore the errors, slowly fix the errors, or demand Grab
fixes it somehow? Can we take lessons from any other projects, say TIGER
2.2 What would even constitute as a fix by Grab? Should we ask them to do
something like fixme=verify_on_ground on the new entries so that it can be
ignored by the routing until verified? At least it will make the map usable
again. Alternatively we identify the sweet spot in (1) and ask Grab to redo
their edits to comply.
3. It's been difficult to agree with the mapping team on a standard. They
did make some statements in this post
seems to highlight a difference of understanding between the community and
the mapping team.
3.1 There doesn't seem to be a way in to enforce a commitment.
Hypothetically if they said "we do QC" then we continue to uncover errors
or “we don’t retag” when clearly this is happening, we can’t stop them.
3.2 Maybe there needs to be a way of assessing mapping activities so new
organized mappers know what would qualify as a high quality contribution.
4. The directed editing policy
<https://wiki.osmfoundation.org/wiki/Directed_Editing_Policy> page gives
some good guidance but I think some best practices are required, complete
with example workflow and KPIs. Maybe this can be related to scale, the
bigger the scale of edits the stricter the quality and the more
transparency required. There can also be a difference between mapped vs
unmapped areas. Has anyone published any such material for their own
mapping projects that we can propose to Grab?
5. I brainstormed some ideas with varying levels of feasibility in case it
can be built upon by others:
- Local Grab mapping team oversee remote work and are responsible for
the remote mapper's edits.
- Mappers are put in small teams with team leaders being personally
responsible for quality.
- Transparency about quality issues, affected changesets, causes and
remedies ie. everything on a public issue tracker.
- Global Logic brings experienced OSMers to their production room
- Global Logic makes their process open so that the community can
identify weaknesses and points of errors
- Bounty: Grab deducts US$5 from Global Logic's remuneration and gives
it as ride credit to local contributors who spot a bug. This would align
- Fork the map, copy it and make changes on their own servers, allow the
community to pull in whatever changes we want into the main map.
Thanks in advance.
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