[Talk-us] Tiger 2007 Data

[Alan Brown]

> Then, decide how if/when it is appropriate to write over the old TIGER

> stuff with new.  Or, to merge it somehow.

Be very, very careful here.

Conflation is a difficult thing.  I used to work at Tele Atlas, and there was a major project to conflate Tele Atlas North American data and GDT data (a company they just acquired).  They had at least a hundred people committed full time to completing the task in a year (I don't know the exact number), with tens of millions in funding - and they failed in a big way.  The head of the North American division got axed as a result.

If there's a particular layer that has useful info, that's not already present - that could be imported successfully.  Otherwise, the most useful thing would be some sort of set-up where someone could view changes to the new TIGER data simultaneously with the OSM data, and choose what to import.   Or - if you can determine if a whole region was untouched - replace previously imported data with new data.

What you don't want to mess up is the careful work people have done to improve the quality of data in a region manually.  If you try to merge data automatically without careful oversight, you could destroy a lot of hard work.  A one-time import - to create a starting point for people to edit - makes all the sense in the world.  Subsequent updates are a much harder thing.

-Alan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk-us/attachments/20081019/0d0e044d/attachment.html>