Hi Ed, (01)
I reckon that your "clear case" can be further sub-classified in an
interesting way. (02)
It looks to me as if one can distinguish between (a) terms/classes whose
definitions (membership conditions) change over time but whose extension
remains the same across time and (b) terms whose extensions change over
time, so are probably not classes in any set-theoretic sense. (03)
An obvious case of the former is membership of the club. Changes in the
rules for membership (a kind of definition) do not change the class of
members. (04)
It seems to me your NIST case can be seen in this way. I'm guessing but I
would expect that for a standards body at any particular time there is an
official definition of a metre and so the extension of the class metre at
any particular time is fixed by the official definition at that time. So
there is a way to regard the extension of the class across time as fixed,
unchanging. In this case, the class does not change.
Outside the standards bodies, it may be more difficult to fix things in this
way given problems in converting existing measurements from one definition
to another; as in your example "some scientific measurements of silicon
deposition and crystal structure, for example, might actually change in the
last decimal place or two, if the instruments were re-calibrated." However,
if it is important enough the effort will be made. If not, these might be
regarded as different concepts/senses. (05)
An example of changing definition over space (rather than time), might be
local times. One can say the new day starts at 00:00 local time - which is
at a different 'global' times in different places - however, the extension
can be seen as fixed, indexed to the time zone. (06)
A case where there is a clear change in extension would be the concept of
species in biology, where this has changed (or is proposed for a change)
from a class of individuals to an individual. It is difficult to see how one
would gerrymander a way of preserving the extension in the case. Your point
about the intent being preserved seems to apply, however it is difficult to
regard oneself as talking about the same thing. (07)
Why this distinction is important is that in the first case there is no need
to think of the reference of the term changing, merely its sense. In the
second case, the reference shifts. (08)
There is quite a literature on this topic, as many people on the list will
know. For example, Ian Hacking wrote on this in Historical Ontology -
http://www.amazon.co.uk/Historical-Ontology-Ian-Hacking/dp/0674016076/ -
referring to Michel Foucault among others. AFAICR one of his examples of
changing concepts was the (Canadian) legal notion of 'refugee' - Foucault
talked about the changes in biological classification. (09)
Regards,
Chris (010)
> -----Original Message-----
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
> bounces@xxxxxxxxxxxxxxxx] On Behalf Of Ed Barkmeyer
> Sent: 16 July 2012 17:02
> To: [ontolog-forum]
> Subject: Re: [ontolog-forum] The concepts can change?
>
>
>
> Ali Hashemi wrote:
> > Dear Matthew and Marcelino,
> >
> > In socially constructed domains, it may be the case that it is useful
> > to model a concept with changing definitions through time.
> >
> > Take for example the medical domain and the definition of a disorder
> > X. In some authoritative medical journal or text at year YYYY, the
> > disorder may be defined as containing certain characteristics. In some
> > future edition of a similar authoritative text, what exactly counts as
> > an X may evolve. It would then be useful / valuable / instructive to
> > scope the definitions of X through time, and in so doing to capture
> > how the different interpretations of X have been applied.
> >
> > Such a scenario is quite common in regulatory and legal domains. A
> > legal concept may be defined (and created) in some article of some
> > legislation and it may be amended at a later date. Arguably, you could
> > model this evolution as two distinct concepts, related by an amending
> > action, though colloquially, the notion of say, "Tax Payer" would
> > remain constant. Modeling the changing definitions of "Tax Payer" is
> > definitely of use to the intended consumer of said legal concepts and
> > from their point of view, there is only one concept under consideration.
> >
> > In such a scenario, the concept of "Tax Payer" was created for a given
> > jurisdiction due to a particular article / section of law, and the
> > meaning of this term may change according to other pieces of
> > legislation (or court decisions) as issued by the relevant legislative
> > authorities in said jurisdiction. Should this jurisdiction (or
> > geo-political entity) cease to exist, the concept of "Tax Payer" may
> > consequently also cease to exist.
> >
> > Best,
> > Ali
>
> Ali makes a point. It is important to distinguish the idea that a concept
may
> have different referents (a different extension) over time from the idea
that
> the 'concept' itself may evolve over time. Matthew addressed the 4-D
> solution to the "changing referents" problem -- make all referents 'states
of
> things' rather than "endurant" things.
>
> We also need to distinguish the evolution of a concept from the
relationship
> between the term and the concept. One can argue that the evolved concept
is
> a new concept and the term has simply been "moved".
> This is not uncommon in some business and social practices, and is a
critical
> feature of "buzzwords" -- the term is applied to a generalization that
includes
> several vaguely related concepts that were formerly distinguished.
>
> One can argue about what happens in the legal domain, but in the science
and
> engineering domains one really does see evolution of a concept. The
problem
> is almost always that the scientific 'concept' is not exactly its
definition.
> Scientists sometimes refer to a 'working definition'.
> What is meant is that there is a set of phenomena that have something in
> common, and the concept is intended to refer to whatever that is.
> Initial observations lead to the working definition; further research
refines that
> notion. In a similar way, engineering folk distinguish between what they
call
> 'concept' and 'design'. The concept is the set of properties the new
thing will
> have, more or less, and the design is the detailed specifications for its
makeup.
> In an engineering 'concept', some properties are critical -- they are what
> creates its value -- but other properties may be important in creating
market
> and distinction from competitors. Those properties are 'softer' -- they
can be
> traded off in the actual design, as long as the design meets the twin
purposes
> of appeal and distinction.
>
> The whole idea of concept evolution is that the original intent -- the
> characterizing properties that motivated the creation of the concept --
does
> not change but the formal intension -- the formal definition of the
concept --
> does.
>
> A clear case from the NIST realm: The international standard 'metre'
> was originally defined to be a particular fraction of the best measurement
of
> the circumference of the earth at the equator in 1875.
> In practice, it was defined by a metal alloy bar that was kept in Paris
and
> carefully cloned for each of the participating national measurement
standards
> organizations. In 1972, the nominal geographical definition was replaced
by
> the wavelength of a readily reproduceable radiation, which happened to be
> the length of the metre bar but measured to many orders of magnitude
> greater refinement, and now independent of the temperature in the room and
> accidental deposition of airborne molecules. The intent never changed.
> Nothing that was 2 metres long became something different, but some
> scientific measurements of silicon deposition and crystal structure, for
> example, might actually change in the last decimal place or two, if the
> instruments were re-calibrated.
> Theretofore, however, those decimal places were a matter of disagreement
> among conforming measurement instruments. The new definition enabled
> better measurement, by establishing a better reference. The important
idea
> here is that the concept -- the intent -- of the metre did not change, but
its
> definition improved.
>
> This is what Ali means when he talks about the 'social' aspect. What is
> important is the intent and the expectations for the use of the concept,
and
> the formal definition can change over time to support those purposes
better.
> Statistically, the change in definition may come to clearly include or
exclude
> 'outlying cases', like the deposition measurements, but that almost always
> means that their former inclusion or exclusion was debatable.
>
> We don't want to excuse "term migration" as "concept evolution", but we do
> have to recognize the existence of true concept evolution in science and
> engineering. (And my concerns have nothing to do with 'social
> domains'.)
>
> -Ed
>
> P.S. I have to say that I owe much of this insight to Eswaran
Subrahmanian.
>
> >
> > On Sat, Jul 14, 2012 at 10:47 AM, Matthew West
> > <dr.matthew.west@xxxxxxxxx <mailto:dr.matthew.west@xxxxxxxxx>>
> wrote:
> >
> > Dear Marcelino,
> >
> >
> >
> > What does it mean to say that concepts can change?
> >
> >
> >
> > MW: For a concept to be able to change would suggest a very
> > unusual usage of the term. Usually the whole idea of a concept is
> > that it refers to the same thing always.
> >
> >
> >
> > It is the case that the meaning of the concepts can change over
> > time? In this case, what is the meaning of meaning? How one can to
> > trace the identity of concepts over time, in order to judge that a
> > (same) concept was changed? What remains the same when occur a
> > change in a concept?
> >
> >
> >
> > MW: These would be excellent questions to ask anyone who suggests
> > that concepts can change.
> >
> >
> >
> > Or it is the case that each meaning is related to a single
> > concept? In this perspective, seems that when we say that a
> > concept was changed, in truth, we have two concepts: the previous
> > concept and a new concept (with a new meaning).
> >
> >
> >
> > MW: This would be the usual usage.
> >
> >
> >
> > Does it make sense to say that a concept can cease to exists?
> >
> >
> >
> > MW: That depends on how you are using the word “concept”. If you
> > are using it as a synonym for class then it probably does not make
> > sense. But one of the usages of concept has it as the
> > representation of some thing in some particular human brain, in
> > which case presumably they cease to exist when the person dies or
> > forgets them.
> >
> >
> >
> > How these questions are related to the practice of ontology
> > engineering?
> >
> >
> >
> > MW: They questions you need to get out of the way.
> >
> >
> >
> >
> >
> > Regards
> >
> >
> >
> > Matthew West
> >
> > Information Junction
> >
> > Tel: +44 1489 880185 <tel:%2B44%201489%20880185>
> >
> > Mobile: +44 750 3385279 <tel:%2B44%20750%203385279>
> >
> > Skype: dr.matthew.west
> >
> > matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
> > <mailto:matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx>
> >
> > http://www.informationjunction.co.uk/
> >
> > http://www.matthew-west.org.uk/
> >
> >
> >
> > This email originates from Information Junction Ltd. Registered in
> > England and Wales No. 6632177.
> >
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> > City, Hertfordshire, SG6 3JE.
> >
> >
> >
> >
> >
> > Best regards.
> >
> >
> >
> >
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> > (•`'·.¸(`'·.¸(•)¸.·'´)¸.·'´•) .,.,
>
> --
> Edward J. Barkmeyer Email: edbark@xxxxxxxx
> National Institute of Standards & Technology Manufacturing Systems
> Integration Division
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