[OSM-talk] The real face of MAPS.ME edits and notes - a short analysis

Roland Olbricht roland.olbricht at gmx.de
Mon Jun 12 11:32:04 UTC 2017


Hello everybody,

first of all, I would like to thank MichaƂ for the analysis. However, 
after cross-checking three random changesets, I come to a different 
conclusion.

https://overpass-api.de/achavi/?changeset=49378841
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.

https://overpass-api.de/achavi/?changeset=49372507
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.

https://overpass-api.de/achavi/?changeset=49385468
This is indeed at best a very vague indication that there is something 
notable.

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 
the world.

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:
https://overpass-turbo.eu/s/pGL
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 
assurance.

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
https://lists.openstreetmap.org/listinfo
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.

Best regards,

Roland



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