Re: SpatialThing and feature (again)

As someone coming purely from the RDF world with little Geo knowledge, I
would like to address some 2 concerns regarding the current conclusion.

- If the classification of objects as geo:Features depends on their
significance in a PARTICULAR universe of discourse, I would argue that in
the open information model that RDF strives to be, anything would classify
as a Feature. The biggest advantage of RDF is the ease in which you can
merge information from different sources. However, what is defined as
"significant" in the original application may not be significant for my own
application. Hence, this definition of Feature makes it obsolete in my eyes.

- Ignoring my former point, the domain definition of geo:hasGeometry
implies that any subject that has the property is in fact a Feature, as
explained earlier in the mail thread. However, following the definition
that a Feature is something of significance, this would imply that I cannot
use this property to attach geometrical information to a subject if that
subject is not significant for my application. Hence, this definition (of
Feature) makes geo:hasGeometry carry undesired side effects.

Both issues would not occur if Feature was in fact defined as being some
kind (real world) spatial thing.

Best regards,
Dieter De Paepe

Ghent University - imec
iGent Tower - Department of Electronics and Information Systems
Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium

> To summarize:
>    - Every ISO 19109 feature is a GeoSPARQL geo:Feature (and GeoSPARQL is
>    consistent with ISO 19109)
>    - E.g., it is correct to state that ex:loan is a geo:Feature
>    - It is not relevant whether it would be semantically correct to
>    attach a geo:hasGeometry property to the feature or not
>    - The main role of geo:hasGeometry in GeoSPARQL is RDFS entailment,
>    that is to infer that every subject of such a statement is a feature and
>    every object is a geometry
>    - Spatial things in our BP are a subset of the ISO 19109 feature -
>    i.e. only those with a "spatial extent"; e.g. ex:loan is not a spatial thing
> Should we clarify the last point in chapter 5 of the BP as currently this
> is not clear?
> Clemens

Received on Tuesday, 18 April 2017 08:13:16 UTC