On Wednesday 11 October 2017, Minh Nguyen wrote: > Great questions. I've attempted to answer a few of them below:
Thanks for the effort - but from my point of view these answers mostly do not actually address the key points of my questions. I have made some progress getting answers to some of the core questions on the German forum (https://forum.openstreetmap.org/viewtopic.php?id=59910&p=3) so far resulting in the following conclusions from my side. * stability of Wikidata IDs seems limited. There seems to be a concept of redirects so an ID can point to a Wikidata object with a different ID and the object formerly under that ID is not necessarily identical to the one it redirects to. To what extent re-structuring of information on Wikidata (that would primarily mean merging and splitting of Wikidata objects) leading to the creation of redirects happens and how much more or less common it is to OSM IDs changing i don't know (and given Wikidata is still very young such information would also be quite unreliable for the future). * there definitely is no 1:1 relationship between Wikidata IDs and OSM objects in general. In particular this is not the case for Wikidata objects covering several concepts that are separately mapped in OSM (where several features in OSM correctly refer to the same Wikidata ID). Also in case of redirects in Wikidata there would be several Wikidata IDs corresponding to the same OSM feature (although you could of course formally define redirects as invalid Wikidata IDs - which however would further limit the stability of those IDs as explained above). * Wikidata is definitely not suited as an universal meta-database connecting OSM with other open data sets. This is because of the Notability concept (https://www.wikidata.org/wiki/Wikidata:Notability) which practically means the vast majority of the >500 million tagged features in OSM will never be able to get a Wikidata ID and will therefore never be able to be connected to other data sets through Wikidata. There are still a lot of things that are unclear to me about the whole "Wikidata in OSM" subject so any further insights into this are welcome. Given that Wikidata cannot function as an universal connector of OSM to other databases (something i was not really aware before) i would in particular like to re-emphasize the question: > * What is the qualification of Wikidata for having its IDs in OSM > (both for wikidata=* and X:wikidata=*)? Is there a particular > objective criterion that qualifies it? Would there be other external > IDs that would also qualify under these criteria? Is there a limit > in the number of different external IDs OSM is going to accept? Please understand that from my side this is truly an open question, not a means to press for removing wikidata IDs from OSM. But it is a question that needs a good answer from my point of view. And deflecting by pointing to other IDs we already have in OSM like leftovers from imports and IDs for specific real world uses does not really help here. > > * To what extent has there been information transferred > > systematically from Wikidata and Wikipedia to OSM based on wikidata > > ID references (like adding names in different languages). As > > others have explained this would be legally problematic and it > > would be important to know how common this is. > > I agree that there are questions about OSM's acceptance of labels and > statements copied from Wikidata, though I would've expected this > phenomenon to be at least as common with Wikipedia long before the > introduction of the wikidata tag. But my question was specifically to what extent data has been transferred based on wikidata ID references. The question if such data transfer happened before based on other connections has nothing to do with this. We definitely have under-the-radar data imports from Wikidata, sometimes partly disguised by moving nodes - but the names matching in all inconsistencies is a clear indicator. Like here: http://www.openstreetmap.org/node/4996439821 http://www.openstreetmap.org/node/5073632521 http://www.openstreetmap.org/node/5121933121 But this is also a different matter unrelated to the Wikidata IDs in OSM. -- Christoph Hormann http://www.imagico.de/ _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
