[OSM-talk] Licence of Facebook's derived road datasets? ODbL?

[Christoph Hormann]

On Friday 15 November 2019, Martin Koppenhoefer wrote:
>
> > From an engineering perspective the idea that adding OSM data can
> > create a derivative database but subtracting OSM data cannot does
> > not hold up of course.  I can create a polygon data set of the
> > Earth surface (a simple rectangle in EPSG:4326) and subtract an OSM
> > derived data set of the Earth land masses from that to get a data
> > set of the oceans. According to the hypothesis this would not be
> > subject to the ODbL.
>
> You are generalizing in a way that is not suitable.

No, i am not, i am falsifying the hypothesis given by providing an 
example that contradicts the hypothesis.

> [...] IMHO
> there isn't OSM data in their dataset.

And neither is there is my ocean data set - the OSM data set used only 
contains land masses, my resulting data set (D2 in Rory's terms) only 
contains oceans.  So no OSM data in it.

> The question is not "addition or subtraction", but whether there
> is data from OSM in the data.

No the question is if when based on the same D1 facebook generates a new 
D2_a using *changed* OSM data the results are *different*.  If that is 
the case D2/D2_a is a derivative of OSM data.

If the question is not "addition or subtraction" consider the following 
scenario.  You create a data set using some AI and big data process 
of 'potential restaurants' world wide and create a set intersection 
between those and the restuarants in OSM would the results be a 
derivative of OSM data?  This would only differ from facebooks road 
data in calculating an intersection rather than a difference as 
facebook does for the roads.

Needless to say i think that if your answer is that this is not an OSM 
derivative that would be a recipe to de-ODBL-ify any subset of OSM 
data.

-- 
Christoph Hormann
http://www.imagico.de/