How to express nominal dqv:values?

In the Multisensor project we have some quality ratings of content items.
These items are called "SIMMO" and have GUID URLs like ms-content:b3f35 (the
actual URL is much longer).
The ratings are: low, medium, high, curated (highest).
Obviously, these are NOMINAL values, not numbers.

I'd like to express them as dqv:QualityMeasurement (more direct), not as
dqv:QualityAnnotation.
I did something like this:

ms:accuracy a dqv:Metric;
  skos:prefLabel "Accuracy"@en;
  skos:definition "Degree to which SIMMO data correctly represents real
world facts."@en;
  dqv:inDimension ldqd:semanticAccuracy;
  dqv:expectedDataType ms:Accuracy.

ms:Accuracy a owl:Class, skos:ConceptScheme;
  rdfs:label "Accuracy values"@en.
ms:accuracy-low a ms:Accuracy, skos:Concept; skos:inScheme ms:Accuracy;
  skos:prefLabel "Low accuracy"@en.
ms:accuracy-medium a ms:Accuracy, skos:Concept; skos:inScheme ms:Accuracy;
  skos:prefLabel "Medium accuracy"@en.
ms:accuracy-high a ms:Accuracy, skos:Concept; skos:inScheme ms:Accuracy;
  skos:prefLabel "High accuracy"@en.
ms:accuracy-curated a ms:Accuracy, skos:Concept; skos:inScheme ms:Accuracy;
  skos:prefLabel "Manually curated"@en;
  skos:note "Highest accuracy"@en.

ms-content:b3f35 dqv:hasQualityMeasurement ms-content:b3f35-quality.
ms-content:b3f35-quality a dqv:QualityMeasurement ;
   dqv:isMeasurementOf ms:accuracy; dqv:value ms:accuracy-curated.

Problems/questions:
1. dqv:expectedDataType rdfs:range xsd:anySimpleType, and as its name
suggests, it's supposed to point to a literal not resource.
   But a nominal value is a resource.
2. I've "collapsed" owl:Class and skos:ConceptScheme in the sense that:
-- ms:Accuracy is both owl:Class and skos:ConceptScheme
-- ms:accuracy-low is both ms:Accuracy and skos:Concept, i.e. has two links
to ms:Accuracy: rdf:type and skos:inScheme.
The reason I did it is because it's most natural to model nominal values in
SKOS; but on the other hand dqv:expectedDataType wants a specific type.
I think this pattern is not flawed, I think I've seen it for SDMX values.

I think that 1 is a problem in the ontology. 2 is a question of modeling
best practice.

Can someone help with the above?
Do you think using nominal values is a significant use case, and thus merits
a place in the DQV spec?

Thanks in advance!

Received on Thursday, 7 July 2016 10:44:47 UTC