For me the question is how to name the precision information. Do not the XSD facets "totalDigits" and "fractionDigits" work well enough? I mean

  .number:totalDigits contains a positive power of ten for precision
  .number:fractionDigits contains a negative power of ten for precision

The use of the word "datatype" is always interesting as somehow it's meant organically different from "the measurement" to which it's related. Both are resources with named properties - what are those names? Certain property names derived from (international standards) should be considered "builtin" to whatever foundation the implementing tool procides.  I suggest that XSD names be used at least for concepts that appear to be the same, with or without the xsd: xml-namespace prefix.

But the word "datatype" fascinates me even more ever since SMW internalized the Datatype namespace. Because to me RDF made an error back when the rdf:type property got the range Class, when it should have been Datatype (though politics got in the way!) It gets more twisted, as now Category is the chosen implementation of rdfs:Class. The problem that presents is that categories are lists and a class (that is, rdf:type value) is, for some singular, and for others a plural, concept or label. Pure semantic mayhem.

I'm happy SMW internalized the datatype namespace to the extent it maps to its software chiefly because it clarifies that a standard "Type" namespace is needed -- which contains singular noun phrases -- which is the value range for rdf:type (if you will) properties. All Measurement types (eg Feet, Height & Lumens) would be represented there too, like any other "class", with its associated properties that (in the case of numerics) would include ".totalDigits" and ".fractionDigits".

Going this route -- establishing a standard Type namespace -- would allow wikis to have a separate vocabulary of singular noun phrases not in the Category namespace. The ultimate goal is to associate a given Type to its implemention as a wiki namespace, subpage or subobject; the Category namespace itself is already overloaded to handle that task.

-john

On 19.12.2012 14:50, Gregor Hagedorn wrote:

totally agree - hopefully XSD facets provide a solid start to meeting those concrete requrements

they don't. They allow to define derived datatypes and thus apply to
the datatype, not the measurement. Different measurements of the same
datatype may be of different precision. --gregor

_______________________________________________
Wikidata-l mailing list
Wikidata-l@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/wikidata-l