Hi Henry, Joshua and All --

I have been lurking in the corner of your most interesting discussion.  Time for my 2 cents worth....

At 07:21 PM 12/21/2005 +0100, Henry wrote:
All of this comes out automatically from having a good ontology. The query mechanism is immediately
defined, and the whole thing is self documenting.

Well, yes, the query mechanism is defined.  But the whole thing aint self-documenting at any kind of comprehensible end user level. 

For example, in our system -- online at the site below -- a few simple rules like this one

estimated demand some-id in some-region is for some-quantity gallons of some-finished-product in some-month of some-year
for estimated demand that-id some-fraction of the order will be some-product from some-refinery
that-quantity * that-fraction = some-amount
for demand that-id that-region for that-quantity that-finished-product we use that-amount that-product from that-refinery 

automatically compile down to a full page of SQL that would be much too complex to write reliably by hand [1].

As another example [2], the free English question "Find genes associated with human diseases" is written by hand as

rulebase trans{ infer {[rdfs:subClassOf] ?a ?c} from
{[rdfs:subClassOf] ?a ?b} and {[rdfs:subClassOf] ?b ?c};
infer {[uni:organism] ?p ?o} from {[rdfs:subClassOf] ?x ?o}
and {[uni:organism] ?p ?x}; }
SELECT TOP 10 ?gene, ?name, ?text USING uniprot RULEBASE trans WHERE
{[uni:organism] ?protein [urn:lsid:uniprot.org:taxonomy:9606]} and
{[rdf:type] ?protein [uni:Protein]} and
{[uni:annotation] ?protein ?annotation} and
{[rdf:type] ?annotation [uni:Disease_Annotation]} and
{[uni:encodedBy] ?protein ?gene} and {[uni:name] ?gene ?name} and
{[rdfs:comment] ?annotation ?text}

As programmers we can have endless fun and employment with long and opaque SQL or SPARQL queries, but they are hardly "self documenting" for scientists or business people -- ultimately the people with the funding.

So, I have to disagree with your  "self-documenting" claim.   With RDF and its data semantics, we are certainly better off than before.  But until we fill the gap indicated in two examples above, with application semantics (e.g as in [3]),  and with at least a smidgeon of real world natural language semantics [4], uptake of the Semantic Web will likely be slow and painful [5].

                             -- Adrian

Online at www.reengineeringllc.com
Shared, community use is FREE.

Adrian Walker
PO Box 1412
CT 06011-1412 USA

Phone: USA 860 583 9677
Cell:    USA  860 830 2085
Fax:    USA  860 314 1029

[1]  www.reengineeringllc.com/Oil_Industry_Supply_Chain_by_Kowalski_and_Walker.pdf

[2]  http://labs.intellidimension.com/uniprot/

[3] Backchain Iteration: Towards a Practical Inference Method that is Simple Enough to be Proved Terminating, Sound and
Complete. Journal of Automated Reasoning, 11:1-22.

[4]  www.reengineeringllc.com/Internet_Business_Logic_e-Government_Presentation.pdf

[5]  Understandability and Semantic Interoperability of Diverse Rules Systems