CDPs in OSM have been an ongoing issue of discussion for a while.
Yup, I wrote here about CDPs getting tangled up with admin_boundary in OSM in 2012! CDPs have no effective or "OSM sensible" admin_level boundary value, I think that much we have established.
NE2 stated that he would delete them all unless someone could show him a single example of them being useful.
Cleaning up messes in OSM (whether by NE2 or not) is something I'm familiar with. Resulting semantics (behavior of how OSM consumers use data in it) can be quite complex: in some cases CDP data confuse, in some cases CDP data might be "all that there is" to get a fix on "where is this?" in a geocoding environment. Usually, going wider (to a county or a state level) might be more strictly accurate, but without the granularity desired. For example, you might be able to "get correct" an admin_level=6 but, 7, 8, 9 or 10, no. (CDPs might be thought of as "somewhere around 7, 8 or 9" but that becomes nonsensical when you truly lean hard on it). There really are a variety of ways OSM's data can be queried and parsed to make sense of things, and CDPs can both muddy the water and occasionally provide "something" which MIGHT BE better than "wider (but correct) something else." With the data as they are today, you just don't always know that in advance.
I pointed out that Bethesda, MD (noted for being where the NIH and the Naval Medical Academy, along with several other large landmarks) is a CDP, as is Silver Spring, MD, which is the 2nd most dense place in MD except for Baltimore. After some discussion, he agreed not to delete the objects in the whole US. The general feeling from many people were that the CDPs were useless information- only interesting to the census workers and not the regular people on the street. For them, it probably made sense to delete the CDPs. For places where CDPs do make sense to keep in, it would be sad if someone deleted them, but that's likely what happened.
See: there IS an odd dichotomy of cases where "using CDPs make some sense" and "CDPs don't make sense." Usually, the latter, but on occasion, more than once, certainly, the former holds true.
This is (yet another) reason why I believe so strongly in Ian's effort to move government boundary data out of OSM and into another dataset.
As tools to move brief (often, relatively brief) snippets of now-in-OSM data get better, easier to use (for intermediate and even novice mappers) and better community consensus hones in on which datasets do and don't belong in OSM, I think we shall see more and more migrations of the sort that Serge refers to. There is a "bare bones" of data which truly do belong in OSM. There are also data which do not belong in OSM. Harmony about which and where can be difficult, as we have seen, but these efforts can and do move us forward. Serge sees a future (of more and more not-in-the-OSM-database data), and it is here now.
What are good ways to keep this happening? Good communication and deeper and wider understandings about how we use our data. And thanks to those who work on OSM data software tools (editors, style sheet manipulators...), promulgate them and document how to use them. Keep up the good work, everybody!
SteveA California _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
