RE: SIMILE Research Drivers

Hi Andy,

> 1/ Just using RDF as a transport format is not really 
> utilizing RDF because the semantics are hidden in the 
> internal processed representation and not necessarily 
> preserved on converting into and out of RDF.  As it is the 
> internal semantics that matter (i.e. are first-class), you 
> might as well use XML for a transport as you are relying on 
> the converters to maintain the semantics across the Web.  

Could you explain what you mean here, perhaps with an example?

One of the big issues that SIMILE (and the Semantic Web as a whole) will have to deal with (IMHO) is that [meta]data is not necessarily going to be 'born RDF'.  One of the main points of the project was, I thought, allowing communities to use their own metadata schemas, most of which won't currently be in RDF ('RDF native').  So, a big research question in SIMILE as I see it is the feasibility of representing all [meta]data in RDF, and how much work it is to translate [meta]data in some other format into RDF.  We have to be able to do this, do it without losing data, without unreasonable effort required, otherwise we're not going to get very far with the RDF approach in this area.

I'm also curious about your use of the word 'semantics'.  How are 'semantics' represented in RDF or any other data format?  My understanding was that the 'semantics' of data were the real-world interpretations of the data.  For example if some resource has a property 'foo:length' that is a literal '30', the semantics of that are that the real-world object that resource represents has a length of 30mm.  This information isn't in the RDF, isn't in the schema; it's not in the computer at all, it's a concept that's fundamentally outside of the computer which is just dealing with symbols.

Is there some other meaning of the word or something else I'm missing?

 Robert Tansley / Hewlett-Packard Laboratories / (+1) 617 551 7624

Received on Monday, 7 April 2003 11:19:13 UTC