Hi Beat

On 10.07.2018 10:13, Estermann Beat wrote:

What we are missing right now in Wikidata is a property to refer to the OSM node ID. I have therefore submitted a property proposal:
https://www.wikidata.org/wiki/Wikidata:Property_proposal/Authority_control#OSM_node_ID
Feel free to add more examples and endorse the proposal. Creation of the property should take about 2 weeks.

I doubt that it's a good idea to create a property for OSM IDs on Wikidata, as OSM IDs aren't "stable". Editors may (and sometimes do) assign new IDs even though the real-world object may still be the same, and previously used IDs might be re-assigned if not currently in use. (See e.g. the vivid history of Node Nr. 1: https://www.openstreetmap.org/node/1)

Instead, OpenStreetMap entities (nodes, ways or relations) with a corresponding Wikidata object should refer to the Q-number (which AFAIK is stable). Determining the corresponding OpenStreetMap object(s) for a Wikidata entry would then require something like an Overpass query, but I can't think of any alternative way to make this linking sound and future-proof.

And feel free to submit a property proposal for OSM ways if you see a need for it.

Dito.

What I don't like in the OSM data is the fact that the source ("survey") does not have proper references (which survey? publication date?).

This is probably a misunderstanding. The source declaration "survey" in OpenStreetMap is understood to mean that the editor observed the represented facts themselves on-the-ground, not that the data stems from some published survey document or dataset. If the information stems from an pre-existing dataset, that specific dataset should be mentioned in the "source" changeset tag.

See the value's explanation at https://wiki.openstreetmap.org/wiki/Key:source#General_sources_commonly_used_by_human_mappers :

The OSM user was there and saw it himself/herself. The OSM user may or may not have done any precision measurement of the location etc. using a device such as a GPS receiver or a theodolite.

Note that use of the "source" tag on OpenStreetMap entities (nodes, ways or relations) is considered historic and (according to the Wiki not officially, but de-facto) deprecated. The tag should be used on changesets instead. Occurrences on nodes, ways or relations should not be taken at face value (they are likely to be outdated or incomplete if the object has been edited since) and should probably be ignored by OSM data consumers and/or augmented with the source information of the complete history of the object.

Regards,
Raphael