[OSM-talk] Ground truth for non-physical objects

Martin Koppenhoefer dieterdreist at gmail.com
Thu Dec 13 11:31:03 UTC 2018



sent from a phone

> On 13. Dec 2018, at 11:40, Tomas Straupis <tomasstraupis at gmail.com> wrote:
> 
> 
>  I was never for indiscriminate, automated imports without manual
> checks. Accepting documents as source does not necessary mean allowing
> such imports. When doing manual checks you can find (and we DO find)
> errors in official documents. Then OpenStreetMap gets correct data,
> not official version.
> 
>  I'm also not saying to remove the ground truth rule as such. I'm
> only saying that the term "ground truth" in the context of
> non-physical objects must be clarified because currently it is being
> interpreted in a lot of different ways.


I would not exclude documents as source for mapping, e.g. you could copy information from a company website, but I would value ground truth higher if there are contradictions. You shouldn’t probably change some existing information based solely on remote research. We even have established specific tags for these, e.g. „official_name“ for a legal name vs. name for the most suitable/common name.


Recently we have been discussing an import of housenumbers in Italy and some people were advocating the removal of housenumbers that the city has suspended, while I was advocating to do this only after a ground survey and having confirmed that the sign has been physically removed (=almost never). Imagine someone standing in front of a housenumber telling her position on the phone, it doesn’t matter if the city thinks it is a valid address, it still serves its purpose, and the person seeing the number will not be able to see whether that number is „valid“ or not.

Cheers, Martin 


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