[OSM-talk] Zero tolerance on imports
ekkehart at gmx.de
Mon Feb 21 11:50:22 GMT 2011
There is a considerable difference between an import into a mostly empty
area - which is rather easy to achieve and mostly helpful - and an import
into an already basically mapped area, which is hard to integrate and where
existing data may be damaged. I believe that this should not happen,
existing survey results should always have precendence over arial imagery or
imported data. I believe that that a proper integration into existing data
is hard to achieve, therefore it should not be done by beginners and it
should be coordinated.
There appears to be a common misconception that arial imagery and imported
data is somehow "better by default" than the hand-drawn traces. Imports
should not duplicate existing data and should not overwrite it. Badly
executed imports can cripple the whole data in an area, replace current
information by obsolete data and badly tagged imports can mess up whole
tagging schemes by suddenly pushing the bad tagging as the majority use.
To make a long story short, I believe that imports should be restricted or
checked very tightly, except for "first" imports into a mostly empty area.
When it comes to motivation, I was very happy to find that my chief area of
interest was mostly empty, with just one major road and the motorway. This
appealed to my sense as an "explorer" who could make a visible difference to
the map. I happily spent a few weekends driving around and mapping all the
secondary roads. When it became available, I appreciated arial imagery as a
help to trace rivers and forests, which are hard to grasp otherwise, but
stopped using it for roads and paths as in later surveys I found that the
impression about the nature of the way derived from the picture was
frequently wrong. A year later the map was mostly complete and it got
boring. So I mapped the routes that I came along anyway, but I did no longer
feel like going out of my way to map a neighboring area - it was already
there, it was usable - why bother?
So, personally, I believe that drawing the first roads on an empty map is
much more fun and motivation than fixing mistakes in someone else's imported
data. If the actuality, accuracy and quality of data is less than excellent,
I would rather not import it at all. Motivated mappers can do better.
View this message in context: http://gis.638310.n2.nabble.com/Zero-tolerance-on-imports-tp6044534p6048406.html
Sent from the General Discussion mailing list archive at Nabble.com.
More information about the talk