[From Rick Marken (950509.1315)]
This discussion of "model based control" is interesting but I think it would
be better to revisit it after we've completed about 10 years of data
collection on everyday control of perception. To date there is almost no
research on the kinds of perceptual variables that people control all
the time. I'd guess that something on the order of 99.9% of the controlling I
do during the day is of good old fashioned perceptions; it seems to me that I
very rarely control imagined (model based) perceptions -- except when I am
I think it would be a good exercise for people getting into PCT (and for
those already into it) to spend some time trying to notice as many of the
variables they are controlling as possible for some period of time during
the day. I did this this morning as I was getting ready to go to work. I
noticed controlling the sound of the alarm clock -- moving my arm as
necessary to get the sound to zero; this is a real control process -- I
have to do it differently every morning because I aalways wake up in a
different position. I also controlled the temperature of the water in the
shower; again a control action because, even in California, the temperature
of the water in the pipes is always different. Then I controlled the
lathering of the soap -- using a different means than I had used the previous
morning due to changes in the size, shape and type of the soap bar. Then I
controlled the dryness of my body, again using different means than the
previous morning due to changes in the absorbancy of the towel that happens
to be hanging on the rack.
Of course, I was always controlling many variables at the same time but
these are just some that I noticed. What I noticed was that 1) I was
affecting the states of variables (loudness of alarm, temperature of water,
latheriness of soap, dryness of skin) 2) bringing these variables to a
desired states (zero loudness, lukewarm, moderate lather, very dry) and 3)
using means that were slightly different than the means I had used on other
occasions to bring these variables to the desired states. I was also able to
notice (or think of) 4) the reason why I had to vary the means I used to
achieve the desired state of the variable (different position on waking,
different temperature in pipes, different shape (or type) of soap bar,
different absorbancy of towel); that is, I noticed the varying disturbances
that required variation in the means used to producethe desired result.
If you can notice these four aspects of your behavior as you go about some
everyday activities, you will be able to see all the perceptual variables you
Controlled variables may not be what everyone likes to think about while they
are going through their morning routine -- but it works for me; and it puts
"model based control" in its proper perspective. Everything I controlled was
a perceptual (not an inferred) variable.
Kim Tan (950507) --
Did OJ do it?
I have my beliefs. But will I ever know (ledge)?
Bill Leach (950508.03:46) gave an excellent response to this one but here's
Given the evidence, I count it as belief that he didn't do it and knowledge
that he did. But, then, given the evidence, I count it as belief that there
is a god and knowledge that there isn't.
I don't know if we will ever know whether or not there is really a god (or
gods) and I don't really care. But I would love to know whether or not OJ
really did it.