speaking of "variables"

CSGnet Archive CSG1999
1

[from Tracy Harms (990319.0930 Pacific)]

Rick Marken (990319.0830), in reply to Bjoern Simonsen:

... There
is no question that, in English, the only appropriate way
to describe control is as the process of bringing _variables_
to predetermined states and protecting them from disturbance.
Do you, perhaps, mean "variable" when you say "object"?

There is no question here in the Control Systems Group. This way of
describing control is widely unknown, however, so many English speakers
necessarily describe it some other way. Insofar as that those
descriptions are inappropriate, it is a failure of theory, not a mistake
of speaking acceptable English.

I think we can elaborate on this key phrase "control is the process of
bringing variables to predetermined states and protecting them from
disturbance." We can expand the term "variable" to this to "variable
aspects", perhaps "variable aspects of objects" or "variable aspects of
things". "Variable" serves better as an adjective than as a noun. The
fact that these aspects are variable is what you are emphasizing.

I suspect that more than a few people have choked on PCT terminology
because they recognize variables only as mathematical abstractions, and
they fail to make the semantic leap to the PCT application of the term.
PCT advocates are typically engineering-minded, and after awhile it
becomes so easy to speak of variables that it is hard to recognize how
others stumble here. I propose that the term "variable aspect" may
facilitate understanding where the stark "variable" has led to
difficulties.

Tracy Harms

2

[From Rick Marken (990320.0820)]

Tracy Harms (990319.0930 Pacific) --

I suspect that more than a few people have choked on PCT
terminology because they recognize variables only as
mathematical abstractions, and they fail to make the semantic
leap to the PCT application of the term.

I think this is a _very_ good point. An important part of learning
PCT -- and seeing it's relevance to everyday life -- is learning
to see the world in terms of _perceptual variables_. I think one
reason we have difficulty seeing the world this way is because
the world we ordinarily encounter is rather static; there is not
much obvious variation going on. My world at the moment consists
of a table of a particular shape and color; walls of a particular
color; pictures on the wall; a lamp of a particular type, etc. It
seems like my perceptions are _constants_, not variable. It
took me a while to realize that most of what I perceive are the
momentary _states_ of perceptual variables -- states that often
remain the same over long periods of time. Variation -- the fact
that perceptions can be in differnet states at different times-- is
not obvious at all. In order to notice this variation we have to use
some reasoning and, if possible, active manipulation.

Reason tells me that the beige of my computer is the _state_ of a
perceptual variable: color. I know this is the case because I can
imagine getting a computer that is a different color. I could also
see this by changing the color of my computer by painting it. Indeed,
all the colors I see right now represent the current states of a
perceptual variable: color. Same with the shapes I see; all are the
states of a perceptual variable: shape. These shapes (like the shape
of my desk) can be made different with some effort. The pictures on
the wall could be different -- the shapes, colors, etc that make up
these pictures could be easily changed by hanging different pictures.
The locations of objects are also variable; the objects are where
they are now but I can change the state of the location variable by
moving the objects or by imagining different states of this variable:
the computer could be over there; the rocking chair over here, etc.

I think one of the first courses in PCT should be about how we can
see our world of experience in terms of perceptual _variables_.
The course would be about how the mathematical abstraction for a
variable (the symbol x) can represent any variable aspect of our
world of experience: x = position of a cursor, color of the walls,
loudness of the radio, toastiness of the bagel, temperature of the
air, neatness of the room, lovingness of a relationship, etc. At any
moment we are typically experiencing a particular state of some or
all of these perceptual variables; but if we pay attention we can
notice that the states of these variables change -- on their own
(like the temperature of the air) or as a result of our efforts to
bring these variables to particular states (like bringing the
toastiness of the bagel to just the right toastiness).

The study of perceptual variables is economical (if not easy)
because it requires only one piece of lab equipment: the mind.
It's the kind of research everyone can do, even those who don't
want to do research.

Again, a _very_ good observation, Tracy!

Best

Rick

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Richard S. Marken Phone or Fax: 310 474-0313
Life Learning Associates e-mail: rmarken@earthlink.net
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