Abbreviations, Using Information

[From Rick Marken (960625.1500)]

Ellery Lanier (960625) --

RMS, CEV, ECU! Give us a break! Stop the graffitti spray. Tell us poor
idiots what the letters stand for.

I'm with you! I'm guilty of the RMS -- but I thought that was a fairly
well known abbreviation for "root mean square" -- very common in science.
But don't blame Bill Powers (or me) for the other abbreviations (or the terms
they stand for). These were contributed by our expert on information theory;
this is why they are so informative;-)

Martin Taylor (960625 16:20) --

I'd agree wholeheartedly: information is not something the control system

Well. That's very nice to know. So why should we care about information?

But the main point I was trying to get across again and again was that
information theory provides an approach to looking at the action of control

As does astrology. So?


That is, the perceptual signal does not contain or carry information
to the control system about disturbances.


That's distinctly NOT a corollary of what Bruce wrote and Bill and I
commended. And I would not expect myself to say it.

OK. So the perceptual signal does contain or carry information to the control
system about disturbances, but the control system doesn't use it. Is that
your point?

The perceptual signal carries information about the disturbance, and if
control is good, this information can be used to reconstruct the disturbance
pretty accurately--as accurately as the perceptual signal is controlled.

Ok. The perceptual signal carries information about the disturbance. But the
control system doesn't use this information; it's like the environment is
continuously calling the control system and informing it about the
disturbance but the phone in the control system is dead. The information in
the perceptual signal is handy, however, because an observer of the control
syetem can tap into the call and reconstruct the disturbance (using all
kinds of other information about the control system and its environment).
Is this what you're saying?

And it wasn't a bad metaphor of Hans' to say that the information is
"consumed" in the process of control.

Isn't "consuming" a way of "using" something? I thought you said control
systems don't _use_ the information about disturbances in perception. Or do
they just consume it without using it? Yes, that must be it! A control
system consuming information must be like a kid swallowing a plastic toy; it
is consumed but not used. No wonder the world is so full of crappy