RE: SUO: Unanimous consent
Dear Matthew and Jay,
some comments
> > -----Original Message-----
> > From: Jay Halcomb [mailto:jhalcomb8@attbi.com]
> > Re: the discussion of acceptability of SUO starter documents,
> > and the lack
[...]
> > Since we currently lack them, this is an opportunity for the group to
> > formulate some at least minimally necessary criteria for
> > acceptability of
> > officially sanctioned starter documents. I suggest, to begin
> > with, that
> > 1)
> > some formal specification of the language of an ontology
> > should be required,
>
> MW: I agree.
My first thought is that we need to declare a common language or a family
thereof. CL comes to mind. Anything like a FOL language should do enough to get
to the core and approximate a good level of formalization. OTOH, I am receptive
to the overload claim. However, remark that a proposer of a document should
provide this service instead of requesting the whole group to get familiar with
yet another syntax.
You cannot expect a group to form, to do the translation job in logical syntax
(which ought to occur, so it seems to me), then axiomatize the intuitions
expressed in a documentation before it starts wondering where
are the putative inconsistencies, gaps and so on. The SUO WG is supposed to do
the second kind of tasks on a starter. At a later level of maturity of the
candidate, issues of adequacy and acceptability might arise in addition.
(Although some such debates should arise when deciding whether a candidate
starter has good chances to success if further developed within this group.)
On second thought, I think the language might not be such an issue, especially
if, as it seems, all we care about is a syntax (in the context of a starter).
From that standpoint, the main advantage of formal logical notation is
readibility (over EXPRESS, say) and absence of ambiguity (over English, say).
Actually, I might not whine at a document presenting tersely in English the
following elements of the theory:
1) gloss of primitive vocabulary (including meta-language as needed)
2) definitions
3) axioms
Options: Examples, Notes explaining informally the background intuition.
> MW: This is available - at least sufficient to build compilers.
> EXPRESS is specified in ISO 10303-11.
Do you have to buy that?
> > and 2) at least some formal axiomatization of content should
> > be required,
> > together with an explicit indication, even if informal, of how
> > axiomatization is intended to be done.
>
> MW: There is some formal axiomatisation. Each line on the diagrams
I'm leery about visual languages. They tend to hide the true conplexity of the
axiomatization and the semantics is far from being obvious usually, if there's
one. More generally, we've had a couple of PDF files with diagrammatic
representations of BFO around for more than a year. Would you find this an
acceptible document? I hope not.
> represents an axiom, some other marks do too. I can appreciate you
> may have as much difficulty determining what they mean as I do with
> KIF. Don't expect sympathy though.
Then try English, just being rigorous. It reads well in your papers. But
really, S-KIF (SUMO) is manageable, CycL even more intuitive imho (just strings
of letters). That kind of things is close enough to plain English with a
slightly weird syntax and impoverished grammar, you can even curse in CycL.
Maybe that's a non native speaker illusion.
The point is that axioms should not be buried as intuitions, be left implicit
or mixed up with informal gloss in the documentation. They should all be
extracted and put naked in a section of a document. They can be commented, if
you use a formalism, they should probably be paraphrased.
> MW: But let us try to quantify this:
I hope this is irony. Seems to me that we're speaking about something that
precisely can't be meaningfully quantified.
> 1. How many concepts should a starter document have:
> a) as a minimum?
1?
According to your ISO habits, it seems that I could start with one concept,
say, individual and claim I have an exhaustive ontology. I guess John Sowa has
probably discussed that kind of ontologies somewhere.
Seriously, if you are clear about your intuitions or the theory you propound,
all the concepts that appear / are used / are necessary (not sure which
criteria are the right ones) in the theory you put forward to provide adeqaute
understanding / expressiveness should be declared.
> b) as a maximum?
The question is meaningful only as concern the defined concepts. I'd say, only
define what allows your to express more tersely the axioms of your theory. No
need to provide a list of concepts by boolean combination if your theory
conatins axioms which would do the job. (Just an example, I hope no SUO does
that, it might work for set theory, but this is dreadful in ontology.)
>
> 2. What ratio of axioms to concepts should a starter document
> contain?
Axioms in the starter should reflect your present understanding and mastery of
your theory. How many principles are there in your theory that you would care
enough to stipulate?
Now, you don't have to shoot for minimality in the case of a starter proposal,
I think. Finding a better axiomatization would be the job of the WG, however,
the point is to find a 'better' one, not to find one, which supposes that
there's one. This would presumably require more understanding of a suitable
logic.
In that connection, it might be that you feel that some principles ought to be
deducible from other axioms. I would list them as axioms in a starter proposal
with such a mention. It would be useful for three reasons:
- this would give a notion of what you consider useful to state (even despite
the fact that you feel that what you state is not so fundamental as not to be
deducible)
- this would provide hints concerning the logic you assume (it's not trivial
for a proposition to be a theorem)
- this would facilitate the job of the group when it comes to work on the
axiomatization
> > Finally, 3) that some
> > characterization of the logical system or systems intended to
> > be employed in
> > automated reasoning over the ontology should be given.
Jay,
I think that we can't expect that from a starter document, unless the document
itself makes claims about the logic. If you request the three numbered items
above, you have a theory. What you do with the theory, how appropriate it is,
which logic it requires and how the axioms might need to be rewritten could be
seen as development of a candidate standard within this group.
But, I agree this is something we want the standard to specify. It seems to me
that a specification of a full logic should be a basic elelemnt of the standard
documents.
> MW: An EXPRESS based system ensures that the axioms specified are
> conformed to by data sets that claim to be models of the ontology.
> Not sure if that counts as automated reasoning. If not, why is
> automated reasoning a necessary purpose? I can appreciate it might
> be where your interest lies.
>
> MW: As it happens my intention would be to develop the material
> from something that had been initially developed for one purpose,
> to something that had wider applicability, but I don't see why
> it should be necessary to complete that before it can be a starter
> document (makes an oxymoron of the "starter" part to me).
> >
> > Each of the 3 criteria above (particularly the formal
> > aspects) will have to
> > be met at some point anyway, if a formal upper ontology is to
> > fit into, say,
> > the IFF framework, or into a lattice of theories.
Yes, but these criteria seems to me global in the context of the Sowa drift, I
mean lattice of theory (or is it registry?)
[...]
>
> MW: I think it is important to be clear about what stage you are at,
> but what I am hearing from some people is that you should necessarily
> start at around the CD level. I think that is a bad idea.
It was fine for the SUO WG to start with a New Item.
Inside this group, you want to have as much as you can at any stage. It might
seem to you that what I suggest is of an high level of completion, but in my
understanding it is not. The main part of the job is review which involves
internal development and comparaison with other starters. And this is nothing
like what I suggest for the starter which is barely explicitation.
The problem is that this group tends not to be productive and to act as a mere
decisional body. You could be more radical than I am and, observing the way
this
group seems to function, claim that there should be no starter at all, only
candidates for being standard. We would just vote on yes and no (no
standardization process here anyway). At some point, when less people use the
word 'ontology' or when most of us changed their carrer objectives, we gather
all the rescapees of the votes put them in a tree (top node is the ontology
with one concept, of course, there would be just one level of leaves, all
ontologies on a par) and call that the Registered Upper-Level Ontology
Standard.
> MW: I think it would be good to establish some process like this with
> associated deliverables. We could adopt the same levels as ISO (but
> rename them) as a start for this.
Oh, I agree with that if you mean turning this discussion list into a working
group, I'm all for it. In that case, it makes sense to qualify what I've said
in the previous paragraph. But I fear we're speaking major procedural debates
for a few years here.
--
Pierre Grenon
IFOMIS Uni Leipzig
Haertelstr. 16-18
04107 Leipzig
http://people.ifomis.uni-leipzig.de/pierre.grenon/
pgrenon@ifomis.uni-leipzig.de
phone: 49(0)351971672
fax: 49(0)3519716179
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