Matthew,
Assuming that the participants actually read the
documentation, do you have difficulty creating descriptive comments for each
term that are sufficiently clear that the differences in the way people use
terms are also clear? i.e. are you not able to write unambiguous
descriptions of the intended meaning of each term?
Genuinely curious about your experiences here.
Pat
Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx
From:
ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Matthew
West
Sent: Friday, January 23, 2009 12:08 PM
To: '[ontolog-forum] '
Subject: Re: [ontolog-forum] Ontological Means for Systems Engineering
Dear Chris,
Yes I agree. One of the biggest temptations is to think that
terms mean what their English language definitions say. I have been having
difficulties with this in the ISO 8000 development, where there is a huge
variance between how people define terms like information and data (very
abstract and academic), vs what people actually describe as information and
data.
Regards
Matthew West
Information Junction
Tel: +44 560 302 3685
Mobile: +44 750 3385279
matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
http://www.matthew-west.org.uk/
This email originates from Information Junction Ltd. Registered
in England and Wales No. 6632177.
Registered office: 2 Brookside, Meadow Way, Letchworth Garden
City, Hertfordshire, SG6 3JE.
From:
ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Chris
Partridge
Sent: 23 January 2009 15:37
To: '[ontolog-forum] '
Subject: Re: [ontolog-forum] Ontological Means for Systems Engineering
Matthew, Ian,
I think buried in here is something quite important, and I am
sure that we have discussed before.
One can roughly categorise two ways of analysing: speculative
and empirical.
Exaggerating slightly. The speculative approach is an armchair
approach that thinks we can get to the essence of things without leaving it.
The empirical approach looks at the evidence (in my case, this is often in
legacy systems).
In the speculative approach, analysts often fixate on a name
– e.g. system – and try and find its essence. They assume an almost
Adamic approach, assuming that some divine power has handed out the names of
the objects from our ontology. Or, more prosaically, that since we use the
names they (that is the type not the token) must consistently refer to
something.
In the empirical approach, one looks at what the names are used
to name. As Ian pointed out, it is certainly true that people use different
tokens of a name in ways that turn out to give very different results –
and Ian has described how these can be disambiguated. One starts from a
descriptive perspective (within a top level framework), but may find that some
revision is required to get an accurate result. Once enough evidence has
emerged (and revision been done), then one can start trying to generalise these
a level. At this stage, a general pattern that covers all uses of the term may
emerge (and debate about what to call it), or it may become apparent that there
are a Wittgensteinian family of senses. What is key, is that our trust of the
higher level pattern is based upon the evidence from earlier use or more
specific patterns – and these play an important role in fixing the sense
of the general pattern. Without the earlier use, there is little or no evidence
for higher level pattern. This is why the evidence gathering is so important.
My suspicion is that a lot of use of terms like system have not
been submitted to sufficient empirical analysis to establish what they refer to
accurately. In the IDEAS workshop there was quite a lot of evidence to support
this view.
Regards,
Chris
From:
ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Matthew
West
Sent: 23 January 2009 14:59
To: ian@xxxxxxxxxxxxxxxx; '[ontolog-forum] '
Subject: Re: [ontolog-forum] Ontological Means for Systems Engineering
Dear Ian,
Then we can add a third class, call it “System” and
put that name in a NameType intentionally constructed by Matthew. The point was
that the name doesn’t matter as long as we can identify the extent of the
class. For example, I might decide to call the class you identified
“widget”. Extensionally, it’s the same class, I just give it
a different name. Because IDEAS/BORO has a sophisticated(ish) naming pattern, I
know that when Canadians say “system” they are referring to a
different class to the one you call “system”.
We didn’t have the option to impose a new definition of “system”
on any of the parties.
[MW] That’s fine. My approach is
usually to try to find the most general sense, and then qualify it to produce
the more restricted senses. This has the advantage of giving you a model that
shows the relationships between them.
They had their own definitions, and a tiny ontology project was
going to stop the combined systems engineering departments of some the largest
defence agencies in the world from doing things their own way. The same goes inside
companies, I should add. This is why corporate taxonomies are all given a
stiff ignoring by the users, and one of the reasons why all those
“corporate data model” projects of the 1990s ended up producing
something no-one ever used. Either the users don’t agree with the
terminology (in which case, they dismiss it off hand), or they see a word they
think they recognise and use the model/taxonomy in an unexpected manner.
[MW] Which is why with the DDM we
(including you) tried hard to preserve the meaning the business gave to terms,
but place them in the ontology such that they were correctly defined by the
relationships they had to other entity types (especially subtype/supertype).
Regards
Matthew
West
Information Junction
Tel: +44 560 302 3685
Mobile: +44 750 3385279
matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
http://www.matthew-west.org.uk/
This email originates from Information Junction Ltd. Registered
in England and Wales No. 6632177.
Registered office: 2 Brookside, Meadow Way, Letchworth Garden
City, Hertfordshire, SG6 3JE.
Cheers
--
Ian Bailey
www.modelfutures.com
From:
ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Matthew
West
Sent: 23 January 2009 13:26
To: ian@xxxxxxxxxxxxxxxx; '[ontolog-forum] '
Subject: Re: [ontolog-forum] Ontological Means for Systems Engineering
Dear Ian,
<snip>
The big challenge in ontology is to figure out what’s
different about a system to any other physical item.
[MW] I agree
Why is a car considered a system, but a rock isn’t, for
example. We had a lot of debates around this in IDEAS meetings. You can
easily ascertain the extents of aircraft, armoured vehicles, etc., but the
extent of the classes each nation were calling system differed. The UK
framework (MODAF) saw a system as any kind of man-made object that had
functionality (i.e. cars=yes, rocks and humans = no). The Canadians were very
specific that a physical object only became a system when it was manned,
maintained and ready to function – a narrower set than the UK one. The US
(DoDAF) description was similar to the UK but also included humans/animals. So,
we had three overlapping classes, each of which was called “system”
by different parties. By extensional analysis, we worked out that what MODAF
calls “CapabilityConfiguration” was an exact match for the Canadian
“System”.
[MW] Well I don’t think any of
those are wrong, but perhaps a little restrictive. The two things that
characterise a system for me are:
1.
It has a function/capability/purpose.
2.
Has parts that can be
replaced by functionally equivalent parts.
Regards
Matthew
West
Information Junction
Tel: +44 560 302 3685
Mobile: +44 750 3385279
matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
http://www.matthew-west.org.uk/
This email originates from Information Junction Ltd. Registered
in England and Wales No. 6632177.
Registered office: 2 Brookside, Meadow Way, Letchworth Garden
City, Hertfordshire, SG6 3JE.
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