- From: Jon Hanna <jon@spin.ie>
- Date: Wed, 2 Jul 2003 12:18:19 +0100
- To: "Roger L. Costello" <costello@mitre.org>, <www-rdf-interest@w3.org>
> An excellent analysis Jon! I believe that your conclusion is correct
> that another level of indirection (i.e., another nesting level) is
> required.
>
> At the moment I have just one comment (I am still working through your
> ideas on expressing conversions, as well as Tom's most recent
> comments). Here is the form that your analysis produced:
>
> <River rdf:ID="Yangtze">
> <length>
> <Length>
> <measurement>
> <LengthInMiles>
> <number>3914</number>
> </LengthInMiles>
> </measurement>
> </Length>
> </length>
> </River>
>
> (I made a few small changes. Let me know if they are not acceptable.)
>
> Here is an alternate form, which is inline with Tom's proposal:
>
> <River rdf:ID="Yangtze">
> <length>
> <Length>
> <measurement>
> <LengthMeasure>
> <transform rdf:resource="LengthInMiles"/>
> <number>3914</number>
> </LengthMeasure>
> </measurement>
> </Length>
> </length>
> </River>
>
> Which of these two forms is preferred? Are there advantages of one over
> the other? /Roger
>
Another way of serialising the first as RDF/XML would be:
<River rdf:ID="Yangtze">
<length>
<Length>
<measurement>
<LengthMeasure>
<rdf:type rdf:resource="LengthInMiles"/>
<number>3914</number>
<LengthMeasure>
</measurement>
</Length>
</length>
</River>
Doing this (and treating LengthInMiles as a subClass of LengthMeasure) shows
that the only real difference between the first and second example is that
the first uses rdf:type instead of transform and that the first allows the
fact that the resource is a LengthMeasure to be deduced from knowledge about
LengthInMiles and/or measurement (subClassOf and range relationships
respectively).
rdf:type is more "natural" RDF to my mind, means something to every RDF
application, and allows for more compact and generally more human-readable
RDF/XML. Unless there were a clear reason not to I would favour rdf:type.
Received on Wednesday, 2 July 2003 07:16:28 UTC