What do you mean I can’t see the nail head sticking up? Explain again why leave out the perceived state? I can’t have anything to compare with the reference signal if I don’t have a perceived state. I understand you can’t observe my perception but we both see what it is I am perceiving.
···
From: Richard Marken [mailto:rsmarken@gmail.com]
Sent: Sunday, November 08, 2015 1:55 PM
To: csgnet@lists.illinois.edu
Subject: Re: The Hammer and Nail Example
[From Rick Marken (2015.11.08.1055)]
Fred Nickols (2015.11.09.0721)–
FN: I think we might be able to fit the hammer and nail example into the spreadsheet. Here’s how I see it. I didn’t find Perceived State in the spreadsheet. Should it be added?
RM: Excellent job Fred! But I would leave “Perceived state” out because it is part of the theory and the aim of the spreadsheet is to describe the observable phenomenon of control as it is seen in various examples of behavior. That is, the aim of the spreadsheet is to describe the phenomenon (control) that the theory (PCT) explains.
RM: There seems to be a strong tendency to deal with PCT purely theoretically. The problem with this is that you lose contact with the reality that the theory is designed to explain.
RM: The importance of understanding the phenomenon that PCT explains before trying to understand how PCT explains it was mentioned by Bill Powers in a video that I stumbled upon yesterday (while searching pctweb for the diagram that Frank Lenk mentioned). The video is here:
https://dl.dropboxusercontent.com/u/70399093/PCT-Part1_x264_002.mp4
In the first few seconds of the video Bill says that he is going to do a demonstration of the phenomenon that the theory is about. Bill says “You have to see the phenomenon and explain it, not the other way around.” The phenomenon, of course, is control. He demonstrates the phenomenon using the rubber band demo. The behavior in the demo can be described as “keeping the knot over the dot”. That behavior can be seen to involve all the observable components of control that are listed in the columns of the “Behavior is Control” spreadsheet: Controlled Variable (position of knot), Reference State (over dot), Means (S pulling on his end of rubber band) and Disturbance (E pulling on the other end of rubber band).
RM: My hope is that by having people analyze many other everyday examples of behavior in terms of the components of control listed in the “Behavior is Control” spreadsheet I can get people to do what Bill tried to do at the beginning of all his major works describing PCT: understand the nature of behavior as control, the phenomenon that PCT explains.
RM: Now I will put your “hammering a nail” example into the spreadsheet with a few clarifications. Here they are
Behavior – (Not sure what to put here)
RM: How about “Hammering a nail into a plank”. That’s what I would say if someone asked me what you were doing.
Context – Inspecting and maintaining appearance of outside deck
Controlled Variable – Nail positiion
Reference State – Nail head flush with deck
Perceived State – Nail head sticking up out of deckk by about half an inch
RM: Again, this is not something you see so it wouldn’t be one of the variables involved in the observable behavior. It’s part of the explanation of the phenomenon, not part of phenomenon itself.
Means (Actions) – Obtaining hammer and using iit to drive nail back down into deck
RM: I think the only action relevant here is swinging the hammer.
Disturbances – Humiidity, outdoor temperature, expansion and contraction of planks, resistance of plank to nail penetration
RM: Excellent!! These are great examples of disturbances.
Type – Program ??
RM: I think “Type” should refer to the type of the variable that is controlled. So I would say that the “Type” is quite “low level” (by Powers’ tentative classification system); probably a configuration – the vertical height of the nail head above the plank.
RM: OK, I’ve entered it in the spreadsheet. Again, I’ll start going over all the example soon.
RM: Thanks for the contribution, Fred!
Best
Rick
Comments – This is a real example from my own experience.
Fred Nickols
From: Richard Marken [mailto:rsmarken@gmail.com]
Sent: Saturday, November 07, 2015 8:05 PM
To: csgnet@lists.illinois.edu
Subject: Re: The Hammer and Nail Example
[ From Rick Marken (2015.11.07.1705)]
Fred Nickols (2015.11.07.1605)
FN: Thanks, Rick. Very helpful. Does “torque� equate to “force� as in “the force with which the hammer strikes the nail�?
RM: Yes, torque is a force. In your example. it is your output – the force exerted by you (your muscles) on the hammer. The force with which the hammer strikes the nail depends on how much torque force you exert on the hammer as well as on the mass of the hammer head. But that force could be called your output as well.
Best
Rick
Fred Nickols
From: Richard Marken [mailto:rsmarken@gmail.com]
Sent: Saturday, November 07, 2015 3:51 PM
To: csgnet@lists.illinois.edu
Subject: Re: SmartDraw File PCT Formal Model.SDR
[From Rick Marken (2015.11.07.1250)]
Fred Nickols (2015.11.07.1405)–
FN: Franklin Lenk’s inquiry prompts a question on my pertaining to the diagram below (a copy I made for my own use, not for publication).
FN: Let’s take a simple live example. I was out on my back deck and noticed a nail sticking up from one of the planks. I got a hammer and pounded it back down.
FN: The controlled variable was the nail. My reference signal for it was “flush with the plank� or “not sticking up.�
RM: Remember, a controlled variable is a variable. So the controlled variable in this situation has to be something like “distance of nail head from top of plank”. The reference is “zero distance” which is the same as “flush with plank”. So your description of the reference is correct.
FN: The output quantity was getting and then swinging a hammer so that it struck the nail on the head and drove it down flush with the plank.
RM: Your output is really just the torque you applied to the hammer. That’s basically the same as “swinging the hammer” so you could verbally describe your output that way.
FN: Now if Qi is the controlled variable, the nail, and Qo is my behavior, I’m left wondering about the box labeled Feedback Function. What are the “physical properties that converted my action or behavior in effect on the nail�? Is it simply “striking the nail with a hammer�?
RM: The feedback function is the “laws of physics” that relate the torque you apply to the hammer, Qo, to the amount of change in the position of the nail, Qi, with each swing. This function depends on the mass of the hammer head, M, and the resistance of the wood, R. So the feedback function will be a physical function, g(), that relates Qo to Qi, taking M and R (at least) into account. So the feedback function is:
Qi = g(Qo,M, R)
RM: I think M and R can be considered disturbances to the state of the controlled variable since their contribution to changes in the value of Qi is independent of yours (Qo). But they are basically constant disturbances.
Best
Rick
![cid:image001.jpg@01D11965.2E9BD190]()
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Regards,
Fred Nickols, CPT
DISTANCE ** CONSULTING**
“Assistance at a Distance�
The Knowledge Workers’ Tool Room
Be sure you measure what you want.
Be sure you want what you measure.
–
Richard S. Marken
www.mindreadings.com
Author of Doing Research on Purpose.
Now available from Amazon or Barnes & Noble
–
Richard S. Marken
www.mindreadings.com
Author of Doing Research on Purpose.
Now available from Amazon or Barnes & Noble
–
Richard S. Marken
www.mindreadings.com
Author of Doing Research on Purpose.
Now available from Amazon or Barnes & Noble
