>? although we have never corresponded before ?

I think we have corresponded before, Sean ? I think we actually even spoke to one another when I was with Eurostep. Do I misremember? J

As for your points, I?m not disputing the value of standards. I?m disputing that is possible to certify the semantics (i.e., meaning) of the use of a particular data element, i.e., that a data value and use of the data element mean what the definition says it?s supposed to mean. Standards for mechanical things (e.g., ?volt? and ?bolt?) are very different than standards that involve language, interpretation, and judgment.

I think your use of the term ?semantic standard? differs somewhat than my interpretation of it. At one point in my life I would have called STEP/PLCS and other such standards ?semantic standards?, but no longer think those words belong next to one another. Standards like STEP/PLCS are data exchange standards, and you can absolutely test syntactic conformance to the standard. You cannot test semantic conformance to the standard, however; at best, you can verify through mock usage (i.e., testing) that two parties are interpreting the standard compatibly.

Which you?ve essentially said in your response: ??tests conformance ?to make sure that new versions of software can interoperate using the standard, and to test that the vendors have the same interpretation of extensions to the standard?. That?s catching and correcting semantic errors by testing for articulation and interpretation errors before they?re uncovered in use. I don?t think this testing will ever be complete enough, though; as the standard ages and business requirements change, new and more semantic errors will occur and the standard will have to adapt.

Perhaps my original objection was based on a misinterpretation of the words you chose to express your original point. J

>The fact that we can have this conversation ? is a testament to the effectiveness of semantic standards,

But even given the richness of natural language, it?s still very easy to mis-communicate. I doubt it will be any different using data to communicate.

Bill

Bill

The fact that we can have this conversation, although we have never corresponded before, is a testament to the effectiveness of semantic standards, starting with the definition of the Volt, the way you wire up the plug on our computers, and all the other thousand standards that contribute to the mechanics of communication. When you buy something on line, you rely on having common semantics for the transaction, starting with the meaning of "$" though to the supplier telling the postal service your zip code (and them understanding it in terms of the geography of the USA).

The answer to your objection comes in two parts:

Firstly, there are already some established ways of checking conformance to semantic standards. The CAx-IF regularly tests conformance of mechanical CAD systems for their conformance to STEP (ISO 10303), both to make sure that new versions of software can interoperate using the standard, and to test that the vendors have the same interpretation of extensions to the standard. I would imagine that similar testing goes on in the commercial sector, for example, for EDIFACT messages. The objective is not to prove conformance to the standard ab initio, but to confirm conformance to the standard, probably after several rounds of bug-fixing.

Secondly, whether or not you require proof of conformance to a semantic standard is a measure of how much risk you are prepared to take. You may not require proof that the Hawaiian Pizza you are ordering actually has ham and pineapple, but if it doesn't it will have only cost you 10ドル and some space in your garbage can. A bolt on an aircraft might also cost only 10,ドル but it might also cost the lives of hundreds of people. The aerospace industry is rightly very choosy about who it trusts to make bolts, and the manufacturers have to go through a relatively expensive certification process.

Just to put this in context, as a major world supplier of defence systems, we supply hundreds of products with millions of components to tens of customers, each of whom also has hundreds of suppliers, as indeed do we. The PLCS standard is being put in place to simplify the support by using a common set of semantics. The problem is not to implement thousands of slightly different PLCS sysstems, but have common systems with common semantics. (BTW the standard is written as a conventional Entity-Relation schema plus a taxonomy to specialise generic elements and rules to tie down particular transactions - almost RDF).

The problem is not that as human beings, we cannot negotiate the meaning of our communications, but rather, whether we can trust our computers to do some of the work for us, without manually checking each step that they have taken. There was a report a year or so ago that someone had developed autonomous agents that had then gone on to develop their own language for communicating with each other. The problem was, nobody knew what they were saying. I do not believe this is the aim of the semantic web.

Sean Barker
BAE SYSTEMS - Advanced Technology Centre Bristol, UK
+44(0) 117 302 8184

BAE Systems (Operations) Limited
Registered Office: Warwick House, PO Box 87, Farnborough Aerospace Centre, Farnborough, Hants, GU14 6YU, UK Registered in England & Wales No: 1996687

---

From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Burkett, William [USA]
Sent: 26 October 2009 12:59
To: [ontolog-forum]
Subject: Re: [ontolog-forum] Wish list for the sematic web

          *** WARNING ***

 This message has originated outside your organisation,

 either from an external partner or the Global Internet. 

   Keep this in mind if you answer this message.

Sean:

In my personal opinion, based on my personal experience, your list starts off with a major misstep:

>1) An examination of methods for certifying that the user semantics for terms matches the definition of the term.

I don?t believe there is any possible way to do this. The semantics of data and the schemas that govern them are created by people (or their software surrogates) using their native linguistic skills, - complete with all the language foibles and inconsistencies that plague human-to-human communication. Consider how much time and money is spent creating legal documents and arguing court cases over what the language in a legal document means ? I think the same interpretative imprecision and vagueness will be present in most data. Note that dictionaries do not assert what a word means (nor do they enforce that meaning), but rather dictionaries document the conventional usage of the term.

I think the main objective of semantic technologies needs to be semantic adaptability: the ability to respond quickly to and correct semantic errors ? much the same way we learn the idiosyncrasies of the way each of us speak and adapt to them.

Bill