[OSM-talk] The real face of MAPS.ME edits and notes - a short analysis
roland.olbricht at gmx.de
Mon Jun 12 11:32:04 UTC 2017
first of all, I would like to thank Michał for the analysis. However,
after cross-checking three random changesets, I come to a different
Somebody has added a pharmacy here, plus its name. There are some extra
tags, which may or may not be useful. But if the phamarcy is there then
this is a useful piece of information.
We the community get from that edit a hint that a street is missing.
Thus we now know that this place is worth visiting to improve the map.
This is indeed at best a very vague indication that there is something
Thus, in total we got meaningful observations from surveyors that were
there. Hence, it would be outright vandalism to revert them.
As often told: OpenStreetMap values local contributions over mechanical
data conversions, regardless whether these are imports or linting. You
can have an opposite mind, we do not harass you on that. Please take a
copy of the database and do whatever processing you like on that database.
As this has been told again and again, I would like to explain it this
time a more explicit way:
The price to reproduce all the on-the-ground mappers' contributions we
have is likely to be somewhere between 4 million and 150 million euros:
to reliably tell where all the pharmacies and all the buldings are, and
what names the streets have, we would have to traverse all the roads in
Germany has a density of 5 km street per 1000 inhabitants, plus
pedestrian-only and cycling ways, which could double the figures. Most
other countries are less dense populated, thus are likely to have more
street length per inhabitant. Even if we conservatively assume that
streets only exist in the developed world then there should be 10
million to 100 million kilometers of streets, pathes and roads in the
world, and it could be more. Driving by car costs about 25 cent for the
car and 15 cent for the time spent. Walking will be more expensive,
because it is much slower, but apparently inevitable on half of the way
grid in the world.
Hence, walking-and-mapping the world would cost somewhere between 4
million and 150 million euros.
By contrast, to find and fix all places with "name" equals "name:pl" in
a neighbourhood is just a click away:
A competent freelancer would build for your within a day or less a
script to drop all such tags from your copy of the database, at 1000 to
2000 euros. Keeping up a server with that scrubbed data may cost another
500 euros per year. Even if you plan to keep your copy online for 20
years then it has a total value of at most 12000 euros.
So, dear bot editors, you are jeopardizing 150 million euros to save
some thousand euros at best. This is why we, the community, ask you to
be extremely cautious or not doing it at all.
Note: even if only 1 in 1000 bots or remote mappers damages only 10
percent of the global data (or 1 in 10 only 0.1 perecent of the data)
then it would be already more economical to force all bots onto a
separated database copy (regardless of their other merits) than to
accept the edits.
> (2) Would it be worth discussing strategies for quality assurance
> somewhere? There doesn't seem to be a mailing list dedicated to this -
> maybe there should be one?
It is everywhere and nowhere. There is no such thing as general quality
If you think that "name:XX" tags that are equal to "name" tags are a
problem then start discussing this with the community. I do remeber a
lot of tagging rule discussions but nobody ever complained about that
specific observation yet.
People will spend attention to you on this mailing list, the tagging
mailing list, and the forum. In addition, special topics have their own
mailing lists, see
Before you start a discussion, you should sift through the wiki and find
all supporting or contradicting statements or places where the
information should also go and enumerate them in the discussion. In a
similar way, watch out for tools that may need to be adjusted for that
assertion and ask them to join the discussion.
Once a consent has been settled, it should be written down in the wiki
and contradicting information in the wiki should be removed.
Other issues about taggging should go through the same process. If you
think that this is a painful process then you are right. But as we are a
community about geodata. Hence, the burden about rules is on those that
what to change rules.
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