# infomysteries

**URL:** <http://discourse.iapct.org/t/infomysteries/14019>\
**Category:** CSG1993\
**Created:** [March 18, 1993, 4:32pm UTC](http://discourse.iapct.org/t/infomysteries/14019 "1993-03-18T16:32:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![\_Avery\_Andrews](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/848f3c/32.png) [@\_Avery\_Andrews](http://discourse.iapct.org/u/_Avery_Andrews)\
**Post date:** [March 18, 1993, 4:32pm UTC](http://discourse.iapct.org/t/infomysteries/14019/1 "1993-03-18T16:32:45Z")

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[Avery Andrews 930318.1121]  
(Rick Marken (930317.1400))

I don't think I'm bluffing about anything (tho have done a bit of  
guessing, some of which was a bit wide of the mark, as Martin recently  
indicated). I'm with you in wanting to know how knowing p(t) lets you  
describe d(t) with fewer bits. I think my little story about noise  
generators is a sufficient basis for saying that information about  
d(t) is somehow present in p(t), but if you don't, fine. After all,  
I do say that it is present in `some mysterious sense' which means I  
don't claim to know what's going on, but only to suspect that something  
interesting is.

On a completely different note, I've just written a little  
implementation of a simple `coordinative structure' via perceptual  
control, vaguely inspired by the Abbs & Winstein work on lip  
movements. There are two little points, driven by thrusters through  
a medium. And there is a reference level for separation of the  
points, so that when they are too far apart the thrusters drive them  
together, & vice versa. The reference level is produced by a square  
wave generator. Finally either of the two points can be `frozen',  
whereupon the other goes further to compensate.

In the grab-bag of possible paper topics, perceptual control as an  
implementation theory of coordinate structures strikes me as having  
some promise.

Avery.Andrews@anu.edu.au

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**Author:** ![Human\_Factors\_Lab](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/h/b3f665/32.png) [@Human\_Factors\_Lab](http://discourse.iapct.org/u/Human_Factors_Lab)\
**Post date:** [March 18, 1993, 4:49am UTC](http://discourse.iapct.org/t/infomysteries/14019/2 "1993-03-18T04:49:06Z")

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[From Rick Marken (930317.2030)]

Avery Andrews (930318.1121)--

> I don't think I'm bluffing about anything (tho have done a bit of  
> guessing, some of which was a bit wide of the mark, as Martin recently  
> indicated).

Sorry. I didn't mean to say that you, personally, were bluffing; I  
was crying out to the vast, faceless, nameless group of experts in  
"technical" information theory; I think a school of knowledge (like  
IT) -- even if it can provide no predictions (as Allan notes) -- should  
at least be able to tell me how to measure the main variable in its  
arsenal -- information. PCT tells us how to measure control, at least.

The program sounds fun, by the way.

> In the grab-bag of possible paper topics, perceptual control as an  
> implementation theory of coordinate structures strikes me as having  
> some promise.

Pardon another self-promotion but two such papers (describing simple  
control model implementations of coordinative strutures -- along with  
experimental tests with humans) have already been published (and reprinted  
in Mind Readings -- both in chapter 6 on Coordination). Both appeared  
in major journals; neither has recieved ANY attention from the coordinative  
structure crowd -- positive or negative. But, hey, they were published;  
sorry about having to sacrifice all those trees for nothing, though.

G'day

Rick