[Avery Andrews 930318.0700]
(Avery Andrews (930317.1514))
>Well, I don't know if I would brag about not having any model
>at all. Just observing is very genteel and all -- but unless you
There are times when a good description is a lot better than a lousy
model, Newton & Maxwell providing famous examples, pre-molecular
genetics another. This may or may not be true for linguistics one
(I suspect that the time for modelling is a lot closer than it
used to be, but it does happen occasionally.
>>Suppose we add to our system
>>two random noise generators, one into p(t), one into o(t), both
>>downstream from where we are taking our measurements. Switching
>>either of these generators on will clearly degrade our information
>>about d(t),
>Wait a minute. What do you mean "clearly degrade"? I thought we
>finally agreed that d(t) is "information" only in the sense that
>it is part of the perceptual signal. When you add noise to p(t)
Due to noise in the channels, our reconstruction of d(t) from p(t)
and o(t) will always be imperfect - that is, it wil differ from the
actual d(t) in a way that one might quantify by integrating the
square of the difference between the actual and reconstructed d(t)
or something like that. Injecting more noise into the channel increases
the divergence, e.g. makes our reconstructed approximation to
d(t) less like the original one. I don't recall agreeing to anything
to the effect that d(t) was or wasn't information.
> Now all you can find out
>from p(t) by knowing o(t) is the sum, d(t) + e(t) which means
>that information about d(t) is not degraded
If you can get perfect information about e(t), which is unrealistic.
In general, you still seem to be ignoring the point that there are two
senses of the term `information' floating around, the `technical'
sense of information in `information theory' that neither of us knows
anything much about, and the ordinary sense, which nobody has any real
theories about (but some people, like Fred Dretske, do have interesting
ideas). In the ordinary sense p(t) alone does not provide info
about d(t), but there seems to be a more mysterious and technical
sense in which the information is `there'. But sorting this out would
require us to actually learn this theory, or at least allow Martin
and Allan to explain the high points to us, without firing off
broadsides of objections to everything they say based on terminological
misunderstanding.
Avery.Andrews@anu.edu.au