# Modeling/Testing

**URL:** <http://discourse.iapct.org/t/modeling-testing/7133>\
**Category:** CSG1992\
**Created:** [March 30, 1992, 2:48am UTC](http://discourse.iapct.org/t/modeling-testing/7133 "1992-03-30T02:48:48Z")\
**Posts on this page:** 1\
**Page:** 1

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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 30, 1992, 2:48am UTC](http://discourse.iapct.org/t/modeling-testing/7133/1 "1992-03-30T02:48:48Z")

</div>

[From Rick Marken (920329 18:40)]  
a  
b  
c  
Doesn't anyone want to comment on my "Behavioral Illusion"  
post? Doesn't that strike some of you as a remarkable  
discovery of Bill's? If there is strong negative feedback then  
stimulus response laws are environmental laws-- not organism laws.  
I would be especially interested in hearing from behavioral  
scientists.

> **···**
>
> ------
> 
> Greg Williams (920329) says to Bill Powers:
> 
> > There ARE a lot of cases where g(r) is demonstrably nonzero. But it is quite a  
> > leap to your general claim. I wish you could see that the worth of HCPT  
> > modelling does not hang on the truth of that generality. In fact, I think  
> > leaving the question of the truth of your generalization open, at least for  
> > now, would boost the credibility of HPCT ideas for many behavioral scientists.  
> > It is a matter of admitting humility until the data are in. That humility in  
> > no way compromises the significance of HPCT in explaining organismic CONTROL,  
> > when it is actually found to be present.
> 
> I agree that HPCT is valuable even if the general claim  
> (that g(r) is always non-zero) is not true. But I don't think  
> that claim is what affects the credibility of HPCT. It is, rather,  
> the implicit assumption on the part of most researchers that g(r)  
> is generally zero -- and that HPCT is unnecessary. What these  
> researchers refuse to accept is the possibility that g(r)  
> MIGHT be large and negative. Because of this, they see  
> no need to test for controlled variables. They simply  
> take their observations at face value and proceed to develop  
> models that are based on the assumption that they are observing  
> the behavior of a g(r) = zero system (a Z system). All PCTers  
> are saying is that g(r) MIGHT be non-zero and, if it is, then  
> they are up shit's creek without a paddle. But they ignore this.  
> I don't think PCT people are making grandiose claims; we  
> are just being ignored. I am perfectly willing to accept the  
> fact that g(r) is always zero. I would be surprised by such a result but  
> I don't want to prejudge. I say "just test for controlled variables";  
> that's all I ask of the people who are developing the "open loop"  
> models. If it turns out that the output variables that they are  
> dealing with are, indeed, generated "open loop" then their models  
> are just fine and I'll be happy; at least they eliminated  
> the possibility that they are dealing with a negative feedback  
> control loop by doing the test.
> 
> Perhaps this message has not been made clearly to the "other side".  
> The message is this: "We (PCTers) have no theoretical ax to grind.  
> We have a theory that explains control and we have used it successfully  
> to model behavior where control is demonstrably involved. We know  
> that if you are dealing with behavior that is part of a negative  
> feedback loop then observed input-output relationships are  
> mirrors of environmental (not organismic) functions. So we  
> heartily suggest that you test for control (negative feedback)  
> before you start developing models of what appears to be  
> cause-effect processes."
> 
> That's ALL we ask. Just test for control -- please! Without  
> such testing we have absolutely no way to evaluate the  
> success of any modeling efforts. We don't say cause-  
> effect models are wrong -- though we suspect that they are  
> most unlikely to be correct. But that is an empirical, not  
> a theoretical question. If all these cause-effect modelers  
> would just start doing the test for controlled variables, then  
> I, for one, would be happy -- whatever the results.
> 
> Regards
> 
> Rick
> 
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
> 
> Richard S. Marken USMail: 10459 Holman Ave  
> The Aerospace Corporation Los Angeles, CA 90024  
> Internet:marken@aerospace.aero.org  
> (310) 336-6214 (day)  
> (310) 474-0313 (evening)