Re: More UCR comments

Thanks for your comments, Clemens! Find my answers inline.

On 2 June 2015 at 22:54, Clemens Portele <portele@interactive-instruments.de
> wrote:

> Dear Frans, Alejandro, all,
>
> a few comments on the current draft - mainly from the background of the
> use case I have contributed. I understand that this will likely be too late
> for the current version, but hope that we can discuss them when we prepare
> the next version. If I should add them as issues or pull requests let me
> know. I have lost overview what the correct process is for which type of
> comment...
>
>
> Requirement 5.20 (linkability) states: *"Spatial data on the Web should
> be linkable (by explicit relationships between different facts in different
> data sets), to other spatial data and to or from other types of data."*
>
> I did not find "fact" in the glossary. On the other hand it has "feature"
> and that is used in other requirements, too. I would therefore propose to
> change "facts" to "features".
>

Makes sense to me. Changed.


>
> Linkability is also relevant for links within a data set. I would
> therefore propose to change "different data sets" to "the same or different
> data sets".
>

I think we can remove then that part referring to data sets, since it does
not mind whether features are linked between data sets or within the same
data set. The req. description would remain like this: "Spatial data on the
Web should be linkable (by explicit relationships between different
features), to other spatial data and to or from other types of data."


> The use case 4.10 (publishing geospatial reference data) also discusses
> the need for a capability to establish implicit links by identifying
> properties in features that are typical candidates for joins. To reflect
> this I would propose to introduce another requirement like "Spatial data on
> the Web should identify the semantics of feature properties in a common way
> to enable joining other types of data with the spatial data. Note: The
> purpose of these joins is typically to georeference the other data."
>

There are two existing reqs., besides the linkability one, that could cover
this situation. First, we have Georeference spatial data
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#GeoreferencedData>,
that would address the typical cases for georeference links. Second, could
the Reference external vocabularies
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#ReferenceExternalVocabularies>
req. address the other cases? Let me know if you want to relate your UC to
any of these reqs.


> Another aspect of use case 4.10 is that it should be possible to determine
> the spatial relation between features in different data sets. Req 5.45
> (spatial operators) may address this - in which case it should be linked to
> 4.10. However, it is not entirely clear what "operators" are in this
> context. Is the idea that any API providing access to a spatial data set
> provides these spatial operators so that I can determine, for example, all
> spatial things in the dataset that 'intersect' in another data set? If yes,
> should this be made explicit, perhaps in a note?
>
>
Yes, I will link your UC to the Spatial operators
<http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#SpatialOperators>
req. I understand from the description of the req. that spatial operators
are properties that define spatial relations between features. Is that
enough for your UC? Have in mind that after the FPWD is announced, we will
go on refining the document, so all these comments are very helpful.


> Finally, the requirement text of 5.56 is the same as in 5.55. This must be
> a copy&paste error.
>

Fixed.

>
> Thanks,
> Clemens
>

Cheers,
Alejandro

-- 
Alejandro Llaves

Ontology Engineering Group (OEG)

Artificial Intelligence Department

Universidad Politécnica de Madrid

Avda. Montepríncipe s/n

Boadilla del Monte, 28660 Madrid, Spain


http://www.oeg-upm.net/index.php/phd/325-allaves


allaves@fi.upm.es