- From: Andrea Perego <andrea.perego@jrc.ec.europa.eu>
- Date: Mon, 18 Apr 2016 07:02:48 +0200
- To: Antoine Isaac <aisaac@few.vu.nl>
- Cc: Riccardo Albertoni <albertoni@ge.imati.cnr.it>, "Heaven, Rachel E." <reh@bgs.ac.uk>, Phil Archer <phila@w3.org>, Linda van den Brink <l.vandenbrink@geonovum.nl>, "public-sdw-comments@w3.org" <public-sdw-comments@w3.org>
Hi, Antoine.
>> [snip]
>>
>> >> 2. As Rachel said earlier in this thread [1], the new ISO 19115
>> >> supports the possibility of specifying resolution as vertical or
>> >> angular distance, and with level of detail.
>> >>
>> >> Based on the DQV example, I guess the first two should be modelled
>> >> as instances of dqv:Metric (:spatialResolutionAsVerticalDistance &
>> >> spatialResolutionAsAngularDistance), whereas the level of detail
>> >> should be specified with a dqv:QualityAnnotation (or a subclass -
>> >> :LevelOfDetail).
>> >>
>> >> Is this correct?
>> >
>> > Sorry, I am not sure to fully understand your question, why do you
>> > think that the level of detail should be expressed as a Annotation?
>>
>> My fault, sorry. I missed to explain the context.
>>
>> I was referring specifically to how this is done in ISO 19115-1:2014,
>> where (as Rachel said [1]) the "level of detail" is specified by using
>> element gco:CharacterString - which is meant to be used with free text
>> / alphanumeric strings (including URLs), and not with numbers (as
>> expected by dqv:value, right?).
>
> OK, so something like in the following examples?
>
> :spatialResolutionAsAngularDistance a dqv:Metric;
> skos:definition "Spatial resolution of a dataset expressed as
> angular distance"@en ;
> dqv:expectedDataType xsd:decimal ;
> dqv:inDimension dqv:precision
> .
+1!
> :myDatasetPrecisionAS a dqv:QualityMeasurement ;
> dqv:isMeasurementOf :spatialResolutionAsAngularDistance ;
> dqv:value "[a fraction of degree]"^^xsd:decimal
> .
I see that "degree" is one of the units of measure listed in wurvoc.org,
so the example above might be re-written as follows:
:myDatasetPrecisionAS a dqv:QualityMeasurement ;
dqv:isMeasurementOf :spatialResolutionAsAngularDistance ;
dqv:value "[a decimal degree]"^^xsd:decimal ;
sdmx-attribute:unitMeasure
<http://www.wurvoc.org/vocabularies/om-1.8/degree> .
Does this make sense?
> :spatialResolutionAsALevelOfDetail a dqv:Metric;
> skos:definition "Spatial resolution of a dataset expressed as level
> of detail"@en ;
> dqv:inDimension dqv:precision
> .
> :myDatasetPrecisionLoD a dqv:QualityMeasurement ;
> dqv:isMeasurementOf :spatialResolutionAsALevelOfDetail ;
> dqv:value X .
> .
>
>
> Note that in the last example, X could be a string as you suggest by
> using gco:CharacterString. It could also be an instance of skos:Concept
> that denotes a level of detail (and this has a prefLabel that
> corresponds to the string one would have expressed in the first way of
> tackling the requirement). In the latter case then we're in a borderline
> case where the value would make stronger the temptation to use
> QualityAnnotation, as the observation is not really a (numerical)
> measure, but something more conceptual (and possibly derived from a
> numerical observation).
Thanks, Antoine. This indeed clarifies the intended use of dqv:value.
So, the range is not formally restricted to a literal (as in daq:value
[1]), but this property is meant to be used with a "quantity", that can
expressed in different ways (a number, free text, a URI reference).
Is this correct?
Cheers,
Andrea
----
[1]http://butterbur04.iai.uni-bonn.de/ontologies/daq/daq#value
Received on Monday, 18 April 2016 05:04:18 UTC