> From: Toby Murray [mailto:toby.mur...@gmail.com] > Subject: Re: [Imports] [Talk-us] Fresno castradal imports > > On Thu, Apr 26, 2012 at 9:39 AM, Martijn van Exel <m...@rtijn.org> wrote: > > Hi, > > > > On Thu, Apr 26, 2012 at 12:54 AM, Paul Norman <penor...@mac.com> > wrote: > >> > >> I happened across an import of Fresno castradal data from mid-2010 in > >> the Fresno area. > >> http://www.openstreetmap.org/?lat=36.77&lon=-119.81&zoom=15 > >> is > >> the general area but I haven't fully explored the extents. For a view > >> of the data, see http://maps.paulnorman.ca/imports/review/fresno.png > >> > > A few observations: > >> > >> 1. It is castradal data. The consensus is against dumping castradal > >> data into OSM. > > > > > > I am not aware of such a consensus - consensus among who? Is it > documented? > > I would expect such a consensus to appear in the Import Guidelines but > > it doesn't. > > Or do you mean there's a consensus against dumping data into OSM in > general? > > If by 'dumping' you mean 'importing without consulting the community > > and without giving proper thought to attribute mapping and > > generalization / normalization of geometries' then yes, I'd say > > there's a consensus against doing that. I don't see why we would not > > cherry-pick useful and good cadastral data for import into OSM, > > however. It may be our only source of things like building outlines > > (are those generally in cadastral data in the > > US?) or address data in many parts. > > > > I don't mean to be nitpicking here, I just want to clarify what this > > consensus actually is so people looking for guidance on importing in > > the future can be more fully informed. > > > > [...] > >> > >> 8. There are duplicate nodes where data was imported on top of other > data. > >> For example, http://www.openstreetmap.org/browse/node/768314177 > >> http://www.openstreetmap.org/browse/node/767799968 > >> http://www.openstreetmap.org/browse/node/767770150 > >> > >> With all of these problems I cannot think of any ways to fix the > >> problems short of reverting the import. The tagging problems could be > >> fixed by a script but the inherent problems of castradal data cannot > >> be fixed without essentially deleting most of the import anyways. > > > > > > Are these problems inherent of cadastral data in general, of this > > dataset in particular, or of the way this import was conducted? > >> > >> > >> I propose to delete unmodified objects from this import. I will > >> attempt to preserve areas like schools and fix them if possible. It > >> should be possible to keep most of them but I won't be able to be > >> sure until I get into the removal. > > > > > > The list of issues is long enough and the issues serious enough to > > warrant a revert. > > What I'm missing from this list is the issue I consider to be the most > > serious, which is that this user apparently has not consulted with > > anyone in the community about this import. Or has he/she? > > > I think the area where there is fairly good consensus is that mass > imports of plot boundaries is not welcome in OSM. There was an attempt > last year at doing this in Arkansas that ended horribly with a blocked > account and a couple hundred thousand empty nodes.
There was also the more recent proposed import of Spanish cadastre data. I've made use of local lots information occasionally but there I'm importing a single object at a time, generally for the name of a school. > In this case we have another instance of someone not considering the > consequences of their import on the OSM community. Even if the data is > good and valid (which doesn't seem to be a proven point in this case) if > current tools are not able to deal with it, perhaps the import should > wait and effort put into improving tools first. There is a lot more awareness of what makes a bad import now than there used to be. _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
