On Feb 19, 2013, at 2:08 AM, John F Sowa wrote:
As David said, the legacy system will not have an 'ontology'
with which any formal 'ontology' could reasonably 'interoperate'.
As I explained to David, legacy systems have been interoperating
quite reasonably for over half a century. As I also explained,
it is not only possible, but very reasonable for systems based
on an explicit *normative* ontology to interoperate with either
legacy systems based on an implicit ontology or with systems
based on a different *normative* ontology.
A slight shift in focus in your response.
What I was trying to say is that legacy systems do not have an ontology available, which I think you formally agree with.
I fully acknowledge that legacy systems have been "interoperating" since the days of handwritten ledgers.
I don't really grok "normative" in the context of legacy systems, since to my experience the chaotic content of legacy systems typically does not adhere to any sort of standards. The "standards" are often the programming style of the last programmer. Over time gets very ugly.
I have a so-called "data dictionary" in my basement from a 1980s banking application. Its form factor is 2 4" 3 ring binders, with a page per "data element." Some pages are less than complete. Major problem is that it's manually prepared documentation & thus contains many errors & omissions.
My argument here is that the system itself—not the representation in a manual, with multiple human steps between original source & pretty documentation—must be the documentation. The old active vs passive data dictionary argument. The active dictionary must feed from the system itself. Put humans in the loop & they will inject all sorts of errors.
Think the telephone game. It's just as real & applicable to adults as it is to pre-schoolers.
The language/lexicon/jargon/acronyms in the system MUST be preserved, represented & accessible, not the human (typically a totally disinterested clerk or even worse, programmer who knows such work is beneath them) interpretation of the what they think the documentation should say.
As you point out—not sure I agree, but I won't make a fuss yet—while a legacy system may not (typically does not) have a formal, accessible ontology—an ontology nontheless is there. Someone just has to dig it out as you did with the VivoMind project.
How long does it take to dig said formal ontology out of the source code? How is the ontology maintained when the system changes?
Interesting questions would be:
- is that original system still in service?
- has the VivoMind documentation/ontology been kept up-to-date?