Controlling datatypes

I don't have a clear articulation of the problem in my mind yet so I 
haven't raised an issue for this.

[[
4.1.9 BPR representations MUST use only the following standard 
datatypes. RDF does not by itself define datatypes to be used for 
literal property values, therefore a set of standard datatypes based on 
[XSD Datatypes] and [RDF] are to be used:
]]

It's a good thing to suggest to applications writers (data producers) 
that sticking to a core set of datatypes can be a benefit 
interoperablity of data.  There is a steady stream of questions on 
forums and mailing lists which show that spurious datatyping, and 
unnecessary language tags, confuse app writers (data consumers).

But a consequence of the current wording is that some data can not be 
used with LDP.

Example 1 -- OGC [1], define a geospatial RDF schema that includes

"1.3.5.1 RDFS Datatype: ogc:WKTLiteral" [2]

and the example given is

"<http://www.opengis.net/def/crs/OGC/1.3/CRS84>
Point(-83.38 33.95)"^^ogc:WKTLiteral

which is an RDF datatype not in the list of BP 4.1.9.

Example 2 -- QUDT [3] defines a datatype for degrees Kelvin.

   http://www.qudt.org/qudt/owl/1.0.0/unit/Instances.html#Kelvin


It has a knock-on effect.  If some vocabulary you want to use defines 
the range of a property using a datatype not in the list (it can be as 
simple as xsd:int or xsd:gYear) the vocabulary itself is effectively 
off-limits.


What is the right balance here?


 Andy

[1] Open Geospatial Consortium
www.opengeospatial.org/

[2] www.w3.org/2011/02/GeoSPARQL.pdf

[3] http://qudt.org/
QUDT - Quantities, Units, Dimensions and Data Types in OWL and XML

Received on Thursday, 20 September 2012 13:45:10 UTC