[From Oded Maler (941013)]:
Bill Powers (941007.0755 MDT)
Oded Maler (941007)--:
Suppose a researcher R wants to test the controlled variable of a
subject S. Suppose his conclusion is X. How is X expressed? Being a
perception it cannot be described in physical terms (maybe except for
simple sensations such as muscle tension).
Who says it can't be described in physical terms? I didn't say that. I
said (or certainly meant to say) only that it can't be described in
_objective_ physical terms -- that is, terms that do not rely on
perceptions for their definitions. All the terms of physics, chemistry,
engineering, etc., rest ultimately on perceptions for their
definitions, don't they?.
If I propose that a person in a tracking experiment is controlling the
position of a cursor on a screen, I measure the cursor position in
pixels from some reference point on the screen. In my experience, what I
see as a certain "number of pixels" on a "screen" is what another person
would tell me he or she sees, too. So I can measure the proposed
controlled variable in a way that others (at least other adult human
beings, if not my cat) would agree is correct, and do the test for the
controlled variable using that measure of the variable. Another person,
using what that person believes to be the same perception I am using to
define the controlled variable, would most likely come to the same
conclusion, that it is under control. Luckily, this seems to work quite
well.
This is true for in very restricted situations under the assumption
that both of you share similar notions of distance perception and
those have similar correlates in the pixles space. (Even here one may
argue that the subject is controlling for some complex temporal
patterns of, say, sensations of his hand muscle and infinitely many
other possible perceptual functions, not necessarily reducible to
pixles). But take the following example: the subject sees a form
on the screen and can use basic cut-paste-brush commends to modify
the picture. The experimenter can do the same (i.e., disturb the
picture by adding\erasing\deforming it. Suppose the subject is
Chinese (an hommage to Searle 
and is controlling for closenss
to some Chinese character (or even worse, his grandmother's face)
can you suggest a way a non-Chinese experimenter can discover this
controlled variable?
This would be easier had there been an "objective"
function, say from pixle-arrays to [0,1] that describes the "Alephood"
of a screen (i.e., how much it resembels the letter Aleph). When such
a function does not exist and the expermineter does not have a perceptual
function corresponding to that letter, I don't see how he can deduce
the controlled variable.
And this is a simplified situation where we assume that all perceptions
are grounded in a finite static array of pixles.
What's the problem, Oded? Do you want to say that we can know the actual
nature of the world outside us by some method other than looking at our
own perceptual signals? If so, I'd like to hear what that method is.
No, but there are degrees.
Bill Powers (941012.0500 MDT):
Oded Maler (941011) --
self-consistent perceptual picture of what the other organism is
controlling, with which other observers (and the behaving system
itself) can agree. That can be done without having to know the nature
of the One True Reality.
First, I think this explains why psychology can *never* become
a science (in the physical science sense of the world). This is
not particular to PCT but inherent in the phenomenon.
But the same situation, exactly, holds in the physical sciences. The physical
sciences consist of observations of instrument readings in a theoretical
(mental) framework which gives them meanings. An instrument does not indicate
what is causing its reading; the cause is part of the theory, and is imagined.
Scientists reach agreement about phenomena by reproducing each others'
instrument readings, and agreeing on a theoretical (perceptual) interpretation
of the readings. The situation is exactly the same as it is when human beings
try to compare any perceptions of anything. "Objective" science is a myth. The
problem of establishing a workable definition of a controlled variable is no
worse than that of establishing the existence and behavior of any physical
variable.
In principle - maybe, but there is a large quantitative difference. The
observables in Newtonian mechanics (force, velocity, etc.) heve a lot
more objectivity in them then perceptual variables in one's head.
--Oded