# \*INTRO TO CSGnet\*

**URL:** <http://discourse.iapct.org/t/intro-to-csgnet/376>\
**Category:** CSG1993\
**Created:** [January 9, 1993, 2:07pm UTC](http://discourse.iapct.org/t/intro-to-csgnet/376 "1993-01-09T14:07:39Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![\_Gary\_A\_Cziko](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/3ab097/32.png) [@\_Gary\_A\_Cziko](http://discourse.iapct.org/u/_Gary_A_Cziko)\
**Post date:** [January 9, 1993, 2:07pm UTC](http://discourse.iapct.org/t/intro-to-csgnet/376/1 "1993-01-09T14:07:39Z")

</div>

INTRODUCTION TO THE CONTROL SYSTEMS GROUP NETWORK (CSGnet)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AND TO THE CONTROL SYSTEMS GROUP  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepared by Dag Forssell 921118.

This introduction provides information about:

&nbsp;&nbsp;&nbsp;Our subject: Perceptual Control Theory  
&nbsp;&nbsp;&nbsp;The evolution of the control paradigm  
&nbsp;&nbsp;&nbsp;Demonstrating the Phenomenon of Control  
&nbsp;&nbsp;&nbsp;The purpose of CSGnet  
&nbsp;&nbsp;&nbsp;CSGnet participants  
&nbsp;&nbsp;&nbsp;Asking questions  
&nbsp;&nbsp;&nbsp;The Control Systems Group  
&nbsp;&nbsp;&nbsp;Subscribing to CSGnet  
&nbsp;&nbsp;&nbsp;How to obtain text and program files  
&nbsp;&nbsp;&nbsp;Literature references

OUR SUBJECT: PERCEPTUAL CONTROL THEORY

Here are two introductions by Bill and Mary Powers:

&nbsp;&nbsp;There have been two paradigms in the behavioral sciences since  
&nbsp;&nbsp;the 1600's. One was the idea that events impinging on  
&nbsp;&nbsp;organisms make them behave as they do. The other, which was  
&nbsp;&nbsp;developed in the 1930's, is PERCEPTUAL CONTROL THEORY (PCT).  
&nbsp;&nbsp;Perceptual Control Theory explains how organisms control what  
&nbsp;&nbsp;happens to them. This means all organisms from the amoeba to  
&nbsp;&nbsp;humankind. It explains why one organism can't control another  
&nbsp;&nbsp;without physical violence. It explains why people deprived of  
&nbsp;&nbsp;any major part of their ability to control soon become  
&nbsp;&nbsp;dysfunctional, lose interest in life, pine away and die. It  
&nbsp;&nbsp;explains what a goal is, how goals relate to action, how  
&nbsp;&nbsp;action affects perceptions and how perceptions define the  
&nbsp;&nbsp;reality in which we live and move and have our being.  
&nbsp;&nbsp;Perceptual Control Theory is the first scientific theory that  
&nbsp;&nbsp;can handle all these phenomena within a single, testable  
&nbsp;&nbsp;concept of how living systems work.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;William T. Powers, November 3, 1991

&nbsp;&nbsp;PERCEPTUAL CONTROL THEORY

&nbsp;&nbsp;While the existence of control mechanisms and processes (such  
&nbsp;&nbsp;as feedback) in living systems is generally recognized, the  
&nbsp;&nbsp;implications of control organization go far beyond what is  
&nbsp;&nbsp;generally accepted. We believe that a fundamental  
&nbsp;&nbsp;characteristic of organisms is their ability to control; that  
&nbsp;&nbsp;they are, in fact, living control systems. To distinguish this  
&nbsp;&nbsp;approach from others using some version of control theory but  
&nbsp;&nbsp;forcing it to fit conventional approaches, we call ours  
&nbsp;&nbsp;Perceptual Control Theory, or PCT.

&nbsp;&nbsp;PCT requires a major shift in thinking from the traditional  
&nbsp;&nbsp;approach: that what is controlled is not behavior, but  
&nbsp;&nbsp;perception. Modelling behavior as a dependent variable, as a  
&nbsp;&nbsp;response to stimuli, provides no explanation for the  
&nbsp;&nbsp;phenomenon of achieving consistent ends through varying means,  
&nbsp;&nbsp;and requires an extensive use of statistics to achieve modest  
&nbsp;&nbsp;(to the point of meaningless) correlations. Attempts to model  
&nbsp;&nbsp;behavior as planned and computed output can be demonstrated to  
&nbsp;&nbsp;require levels of precise calculation that are unobtainable in  
&nbsp;&nbsp;a physical system, and impossible in a real environment that  
&nbsp;&nbsp;is changing from one moment to the next. The PCT model views  
&nbsp;&nbsp;behavior as the means by which a perceived state of affairs is  
&nbsp;&nbsp;brought to and maintained at a reference state. This approach  
&nbsp;&nbsp;provides a physically plausible explanation for the  
&nbsp;&nbsp;consistency of outcomes and the variability of means.

&nbsp;&nbsp;The PCT model has been used to simulate phenomena as diverse  
&nbsp;&nbsp;as bacterial chemotaxis, tracking a target, and behavior in  
&nbsp;&nbsp;crowds. In its elaborated form, a hierarchy of perceptual  
&nbsp;&nbsp;control systems (HPCT), it has lent itself to a computer  
&nbsp;&nbsp;simulation of tracking, including learning to track, and to  
&nbsp;&nbsp;new approaches to education, management, and psychotherapy.

&nbsp;&nbsp;Control systems are not new in the life sciences. However,  
&nbsp;&nbsp;numerous misapprehensions exist, passed down from what was  
&nbsp;&nbsp;learned about control theory by non-engineers 40 or 50 years  
&nbsp;&nbsp;ago without further reference to newer developments or  
&nbsp;&nbsp;correction of initial misunderstandings. References in the  
&nbsp;&nbsp;literature to the desirability of positive feedback and the  
&nbsp;&nbsp;assertion that systems with feedback are slower than S-R  
&nbsp;&nbsp;systems are simply false, and concerns about stability are  
&nbsp;&nbsp;unfounded.

&nbsp;&nbsp;The primary barrier to the adoption of PCT concepts is the  
&nbsp;&nbsp;belief - or hope - that control theory can simply be absorbed  
&nbsp;&nbsp;into the mainstream life sciences without disturbing the  
&nbsp;&nbsp;status quo. It is very hard to believe that one's training and  
&nbsp;&nbsp;life work, and that of one's mentors, and their mentors, must  
&nbsp;&nbsp;be fundamentally revised. Therefore, PCT appeals to those who  
&nbsp;&nbsp;feel some dissatisfaction with the status quo, or who are  
&nbsp;&nbsp;attracted to the idea of a generative model with broad  
&nbsp;&nbsp;application throughout the life sciences (plus AI and  
&nbsp;&nbsp;robotics). There are very few people working in PCT research.  
&nbsp;&nbsp;Much of its promise is still simply promise, and it meets  
&nbsp;&nbsp;resistance from all sides. It is frustrating but also  
&nbsp;&nbsp;tremendously exciting to be a part of the group who believe  
&nbsp;&nbsp;that they are participating in the birth of a true science of  
&nbsp;&nbsp;life.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mary Powers, November 1992

THE EVOLUTION OF THE CONTROL PARADIGM

The PCT paradigm originates in 1927, when an engineer named  
Harold Black invented the negative feedback amplifier, which is  
a control device. This invention led to the development of  
purposeful machines. Purposeful machines have built-in intent to  
achieve consistent ends by variable means under changing  
conditions.

The discovery and formalization of the phenomenon of control is  
the first alternative to the cause-effect perspective ever  
proposed in any science.

The first discussion of purposeful machines and people came in  
1943 in a paper called: Behavior, Purpose and Teleology by  
Rosenblueth, Wiener and Bigelow. This paper also argued that  
purpose belongs in science as a real phenomenon in the present.  
Purpose does not mean that somehow the future influences the  
present.

The first specific suggestion on how to use the concept of  
control to understand people came in 1957 in a paper entitled:  
A General Feedback Theory of Human Behavior by McFarland, Powers  
and Clark.

In 1973 William T. (Bill) Powers published a seminal book called  
"Behavior: the Control of Perception," which still is the major  
reference for PCT. See literature below.

This book spells out a complete model of how the human brain and  
nervous system works like a living perceptual control system.  
Our brain can be viewed as a system that controls its own  
perceptions. This view suggests explanations for many previously  
mysterious aspects of how people interact with their world.

Perceptual Control Theory has been accepted by independently  
thinking psychologists, scientists and other interested people.  
The result is that an association has been formed (the Control  
System Group), several books published, this CSGnet set up and  
that at latest count 16 professors are teaching PCT in American  
universities today.

DEMONSTRATING THE PHENOMENON OF CONTROL

The phenomenon of control is largely unrecognized in science  
today. It is not well understood in important aspects even by  
many control engineers. Yet the phenomenon of control, when it  
is recognized and understood, provides a powerful enhancement to  
scientific perspectives.

It is essential to recognize that this phenomenon exists and  
deserves an explanation before any of the discourse on CSGnet  
will make sense.

Please download the introductory demonstration dem1a.exe, which  
is an interactive program and/or rubberbd.txt, which is a text  
telling you how to demonstrate the phenomenon to yourself and a  
friend using only two rubber bands.

THE PURPOSE OF CSGnet:

CSGnet provides a forum for development, use and testing of PCT.

CSGnet PARTICIPANTS

Many interests and backgrounds are represented here. Psychology,  
Sociology, Linguistics, Artificial Intelligence, Robotics,  
Social Work, Neurology, Modeling and Testing. All are  
represented and discussed. As of December 1992 there were  
over 130 individuals from 18 countries subscribed to CSGnet.

ASKING QUESTIONS

Please introduce yourself with a statement of your professional  
interests and background. It will help someone answer if you  
spell out which demonstrations, introductory papers and  
references you have taken the time to digest.

THE CONTROL SYSTEMS GROUP

The CSG is an organization of people in the behavioral, social,  
and life sciences who see the potential in PCT for increased  
understanding in their own fields and for the unification of  
diverse and fragmented specialties.

Annual dues are $45 for full members and $5 for students  
(subsidized).

An annual meeting is held in Durango, Colorado, on the campus of  
Fort Lewis College. In 1993 it will begin in the evening of  
Wednesday, July 28, and end Sunday morning, Aug, 1. There will  
be 7 plenary meetings (mornings and evenings), with afternoons,  
mealtimes, and late night free for further discussion or  
recreation. Full details will be available on the net or by mail  
after April 1, 1993.

Net subscribers find it useful to have thematic collections of  
some of the network discussions, and it enables non-net members  
to keep up with them. Threads from this net are published on a  
quarterly basis in a booklet called the Closed Loop. These  
booklets are distributed to members and are available  
separately. A complimentary copy of Closed Loop will be sent  
upon request. Back issues are available: Volume 1 (4 issues) is  
$12. Single issues of Volume 2, beginning with Jan. 1992, are $6  
each.

For membership information and back issues of Closed Loop,  
write: CSG, c/o Mary Powers, 73 Ridge Place CR 510, Durango, CO  
81301-8136.

SUBSCRIBING TO CSGnet

When you subscribe to CSGnet, you get this message,  
CSGINTRO.DOC. But you may have received it from a friend who  
printed it, seen it on a demodisk, or seen it on Usenet. To  
subscribe, send a message as follows: (Internet address followed  
by two message commands, one per line)

&nbsp;&nbsp;LISTSERV@VMD.CSO.UIUC.EDU  
&nbsp;&nbsp;Subscribe CSG-L Lastname, Firstname, Affiliation, City, State.  
&nbsp;&nbsp;help

(Lastname, Firstname, etc is optional commentary, but helpful).  
("help" requests a list of most commonly used commands).  
(The Bitnet address is: LISTSERV@UIUCVMD).  
(This server is not sensitive to upper or lower case letters).

CSGnet can also be accessed via Usenet (NetNews) where it is  
listed as the newsgroup bit.listserv.csg-l.

For more information about accessing CSGnet, contact Gary Cziko,  
the network manager, at G-CZIKO@UIUC.EDU

HOW TO OBTAIN TEXT AND PROGRAM FILES

A number of ASCII documents and binary computer programs are  
available on a fileserver maintained by Bill Silvert. It is  
possible to download all these files via e-mail. If you are on  
internet, it is easiest to obtain binary program files via  
anonymous FTP. If you are on MCI mail, you have read about how  
you can transfer binary files with Kermit or Zmodem protocols.  
(Type help at the MCI mail prompt for directions). But the  
server cannot send binary files over the internet mail network,  
so download uue.scr first, then request the binary files  
uuencoded as ASCII files. The Internet address for the server is  
BIOME.BIO.NS.CA. CSGnet files are kept in the subdirectory  
pub/csg.

To get basic information and a current listing of available  
documents, send a message as follows: (Internet)

Commands: help  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ftp  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;get csg/Index  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end

"help" requests commands and explanations.  
"ftp" asks details on anonymous FTP for internet.  
"get csg/Index" requests the Index for the csg subdirectory.

Pay attention to letter case for commands! DOS is not dos.

As part of the index (of the csg directory), you may be looking  
at:

programs/msdos:  
dem1a.exe 128437 Bill Power's demonstr of perceptual control  
dem2a.exe 123649 Bill Power's modelling of control

documents/forssell:  
uud.scr 53406 ASCII Compile uud.exe w DOS debug Dir @ end.

If you want dem1a.exe (uuencoded) to get a "live" demonstration  
of the phenomenon of control, and the ASCII file uud.scr with  
directions at the end on how to use DOS debug to compile uud.exe  
to decode it, send the following message commands:

uue csg/programs/msdos/dem1a.exe  
get csg/programs/forssell/uud.scr

The uuencoded dem1a.exe will be sent in four parts. Remove  
headers and use an editor to make it into one file (starting  
with table and ending with end) before you use uud.exe to  
restore the file. dem1a.exe is a self-extracting archive file.  
Put it in it's own directory before you execute it. You get  
complete documentation and a running program.

LITERATURE REFERENCES

For a complete list of CSG-related publications, get the file  
biblio.pct from the fileserver as described above. Here are some  
selected books and papers on Perceptual Control Theory (entries preceded by  
an asterisk are available from The Control Systems Group, 460 Black Lick  
Road, Gravel Switch, KY 40328).

Powers, William T. (1973). \_Behavior: The control of  
perception\_. Hawthorne, NY: Aldine DeGruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The basic text.

\*Robertson, Richard J. and Powers, William T. (Eds.). (1990).  
\_Introduction to modern psychology: The control theory view\_.  
Gravel Switch, KY: CSG Book. ($25 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;College-level text.

\*Powers, William T. (1989). \_Living control systems: Selected  
papers\_. Gravel Switch, KY: CSG Books. ($16.50 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously published papers, 1960-1988.

\*Powers, William T. (1992). \_Living control systems II: Selected  
papers\_. Gravel Switch, KY: CSG Books. ($22 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously unpublished papers, 1959-1990.

\*Marken, Richard S. (1992). \_Mind readings: Experimental studies  
of purpose\_. Gravel Switch, KY: CSG Books. ($18 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Research papers exploring control.

Marken, Richard S. (Ed.). (1990). Purposeful Behavior: The  
control theory approach. \_American Behavioral Scientist\_,  
\_34\_(1). (Thousand Oaks, CA: Sage Publications)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11 articles on control theory.

Runkel, Philip J. (1990). \_Casting nets and testing specimens\_.  
New York: Praeger.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;When statistics are appropriate; when models are required.

Hershberger, Wayne. (Ed.). (1989). \_Volitional action: Conation  
and control\_ (Advances in Psychology No. 62). NY: North-Holland.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;25 articles (not all PCT)

Ford, Edward E. (1989). \_Freedom from stress\_. Scottsdale AZ:  
Brandt Publishing.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A self-help book. PCT in a counseling framework.

Gibbons, Hugh. (1990). \_The death of Jeffrey Stapleton:  
Exploring the way lawyers think\_. Concord, NH: Franklin Pierce  
Law Center.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A text for law students using control theory.

McClelland, Kent. (1992). \_Perceptual control and sociological  
theory\_. Not yet published. Available from the author,  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Grinnell University, Grinnell, Iowa.

McPhail, Clark. (1990). \_The myth of the madding crowd\_.  
New York: Aldine de Gruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduces control theory to explain group behavior.

McPhail, Clark., Powers, William T., & Tucker, Charles W.  
(1992). Simulating individual and collective action In temporary  
gatherings. \_Social Science Computer Review\_, \_10\_(1), 1-28.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Computer simulation of control systems in groups.

Petrie, Hugh G. (1981). \_The dilemma of inquiry and learning\_.  
Chicago: University of Chicago Press

> **···**
>
> To: SERVER@BIOME.BIO.NS.CA.

---

<div class="post-metadata">

**Author:** ![\_Gary\_A\_Cziko](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/3ab097/32.png) [@\_Gary\_A\_Cziko](http://discourse.iapct.org/u/_Gary_A_Cziko)\
**Post date:** [February 3, 1994, 8:51pm UTC](http://discourse.iapct.org/t/intro-to-csgnet/376/2 "1994-02-03T20:51:08Z")

</div>

INTRODUCTION TO THE CONTROL SYSTEMS GROUP (CSG)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AND THE CONTROL SYSTEMS GROUP NETWORK(CSGnet)

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepared by Dag Forssell 1992.11.18  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Updated by Gary Cziko 1994.01.08

This introduction provides information about:

&nbsp;&nbsp;&nbsp;Our subject: Perceptual Control Theory  
&nbsp;&nbsp;&nbsp;The evolution of the control paradigm  
&nbsp;&nbsp;&nbsp;Demonstrating the Phenomenon of Control  
&nbsp;&nbsp;&nbsp;The purpose of CSGnet  
&nbsp;&nbsp;&nbsp;CSGnet participants  
&nbsp;&nbsp;&nbsp;Asking questions  
&nbsp;&nbsp;&nbsp;The Control Systems Group  
&nbsp;&nbsp;&nbsp;Subscribing to CSGnet  
&nbsp;&nbsp;&nbsp;How to obtain text and program files  
&nbsp;&nbsp;&nbsp;Literature references  
&nbsp;&nbsp;&nbsp;CSG Book Order Form

OUR SUBJECT: PERCEPTUAL CONTROL THEORY

Here are two introductions by Bill and Mary Powers:

&nbsp;&nbsp;There have been two paradigms in the behavioral sciences since  
&nbsp;&nbsp;the 1600's. One was the idea that events impinging on  
&nbsp;&nbsp;organisms make them behave as they do. The other, which was  
&nbsp;&nbsp;developed in the 1930's, is PERCEPTUAL CONTROL THEORY (PCT).  
&nbsp;&nbsp;Perceptual Control Theory explains how organisms control what  
&nbsp;&nbsp;happens to them. This means all organisms from the amoeba to  
&nbsp;&nbsp;humankind. It explains why one organism can't control another  
&nbsp;&nbsp;without physical violence. It explains why people deprived of  
&nbsp;&nbsp;any major part of their ability to control soon become  
&nbsp;&nbsp;dysfunctional, lose interest in life, pine away and die. It  
&nbsp;&nbsp;explains what a goal is, how goals relate to action, how  
&nbsp;&nbsp;action affects perceptions and how perceptions define the  
&nbsp;&nbsp;reality in which we live and move and have our being.  
&nbsp;&nbsp;Perceptual Control Theory is the first scientific theory that  
&nbsp;&nbsp;can handle all these phenomena within a single, testable  
&nbsp;&nbsp;concept of how living systems work.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;William T. Powers, November 3, 1991

&nbsp;&nbsp;PERCEPTUAL CONTROL THEORY

&nbsp;&nbsp;While the existence of control mechanisms and processes (such  
&nbsp;&nbsp;as feedback) in living systems is generally recognized, the  
&nbsp;&nbsp;implications of control organization go far beyond what is  
&nbsp;&nbsp;generally accepted. We believe that a fundamental  
&nbsp;&nbsp;characteristic of organisms is their ability to control; that  
&nbsp;&nbsp;they are, in fact, living control systems. To distinguish this  
&nbsp;&nbsp;approach from others using some version of control theory but  
&nbsp;&nbsp;forcing it to fit conventional approaches, we call ours  
&nbsp;&nbsp;Perceptual Control Theory, or PCT.

&nbsp;&nbsp;PCT requires a major shift in thinking from the traditional  
&nbsp;&nbsp;approach: that what is controlled is not behavior, but  
&nbsp;&nbsp;perception. Modelling behavior as a dependent variable, as a  
&nbsp;&nbsp;response to stimuli, provides no explanation for the  
&nbsp;&nbsp;phenomenon of achieving consistent ends through varying means,  
&nbsp;&nbsp;and requires an extensive use of statistics to achieve modest  
&nbsp;&nbsp;(to the point of meaningless) correlations. Attempts to model  
&nbsp;&nbsp;behavior as planned and computed output can be demonstrated to  
&nbsp;&nbsp;require levels of precise calculation that are unobtainable in  
&nbsp;&nbsp;a physical system, and impossible in a real environment that  
&nbsp;&nbsp;is changing from one moment to the next. The PCT model views  
&nbsp;&nbsp;behavior as the means by which a perceived state of affairs is  
&nbsp;&nbsp;brought to and maintained at a reference state. This approach  
&nbsp;&nbsp;provides a physically plausible explanation for the  
&nbsp;&nbsp;consistency of outcomes and the variability of means.

&nbsp;&nbsp;The PCT model has been used to simulate phenomena as diverse  
&nbsp;&nbsp;as bacterial chemotaxis, tracking a target, and behavior in  
&nbsp;&nbsp;crowds. In its elaborated form, a hierarchy of perceptual  
&nbsp;&nbsp;control systems (HPCT), it has lent itself to a computer  
&nbsp;&nbsp;simulation of tracking, including learning to track, and to  
&nbsp;&nbsp;new approaches to education, management, and psychotherapy.

&nbsp;&nbsp;Control systems are not new in the life sciences. However,  
&nbsp;&nbsp;numerous misapprehensions exist, passed down from what was  
&nbsp;&nbsp;learned about control theory by non-engineers 40 or 50 years  
&nbsp;&nbsp;ago without further reference to newer developments or  
&nbsp;&nbsp;correction of initial misunderstandings. References in the  
&nbsp;&nbsp;literature to the desirability of positive feedback and the  
&nbsp;&nbsp;assertion that systems with feedback are slower than S-R  
&nbsp;&nbsp;systems are simply false, and concerns about stability are  
&nbsp;&nbsp;unfounded.

&nbsp;&nbsp;The primary barrier to the adoption of PCT concepts is the  
&nbsp;&nbsp;belief - or hope - that control theory can simply be absorbed  
&nbsp;&nbsp;into the mainstream life sciences without disturbing the  
&nbsp;&nbsp;status quo. It is very hard to believe that one's training and  
&nbsp;&nbsp;life work, and that of one's mentors, and their mentors, must  
&nbsp;&nbsp;be fundamentally revised. Therefore, PCT appeals to those who  
&nbsp;&nbsp;feel some dissatisfaction with the status quo, or who are  
&nbsp;&nbsp;attracted to the idea of a generative model with broad  
&nbsp;&nbsp;application throughout the life sciences (plus AI and  
&nbsp;&nbsp;robotics). There are very few people working in PCT research.  
&nbsp;&nbsp;Much of its promise is still simply promise, and it meets  
&nbsp;&nbsp;resistance from all sides. It is frustrating but also  
&nbsp;&nbsp;tremendously exciting to be a part of the group who believe  
&nbsp;&nbsp;that they are participating in the birth of a true science of  
&nbsp;&nbsp;life.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mary Powers, November 1992

THE EVOLUTION OF THE CONTROL PARADIGM

The PCT paradigm originates in 1927, when an engineer named  
Harold Black recognized and clearly described a closed loop  
control system as a special kind of mechanism. He was working  
with the negative feedback amplifier, which is a control device.  
This led to a new engineering discipline and the development  
of many purposeful machines. Purposeful machines have built-in  
intent to achieve consistent ends by variable means under  
changing conditions.

The discovery and formalization of the phenomenon of control is  
the first alternative to the cause-effect perspective ever  
proposed in any science.

The first discussion of purposeful machines and people came in  
1943 in a paper called: Behavior, Purpose and Teleology by  
Rosenblueth, Wiener and Bigelow. This paper also argued that  
purpose belongs in science as a real phenomenon in the present.  
Purpose does not mean that somehow the future influences the  
present.

The first specific suggestion on how to use the concept of  
control to understand people came in 1957 in a paper entitled:  
A General Feedback Theory of Human Behavior by McFarland, Powers  
and Clark.

In 1973 William T. (Bill) Powers published a seminal book called  
"Behavior: the Control of Perception," which still is the major  
reference for PCT. See literature below.

This book spells out a complete model of how the human brain and  
nervous system works like a living perceptual control system.  
Our brain can be viewed as a system that controls its own  
perceptions. This view suggests explanations for many previously  
mysterious aspects of how people interact with their world.

Perceptual Control Theory has been accepted by independently  
thinking psychologists, scientists and other interested people.  
The result is that an association has been formed (the Control  
System Group), several books published, this CSGnet set up and  
that at latest count 16 professors are teaching PCT in American  
universities today.

DEMONSTRATING THE PHENOMENON OF CONTROL

The phenomenon of control is largely unrecognized in science  
today. It is not well understood in important aspects even by  
many control engineers. Yet the phenomenon of control, when it  
is recognized and understood, provides a powerful enhancement to  
scientific perspectives.

It is essential to recognize that this phenomenon exists and  
deserves an explanation before any of the discourse on CSGnet  
will make sense.

Please download the introductory demonstration dem1a.exe, which  
is an interactive program and/or rubberbd.txt, which is a text  
telling you how to demonstrate the phenomenon to yourself and a  
friend using only two rubber bands.

THE PURPOSE OF CSGnet:

CSGnet provides a forum for development, use and testing of PCT.

CSGnet PARTICIPANTS

Many interests and backgrounds are represented here. Psychology,  
Sociology, Linguistics, Artificial Intelligence, Robotics,  
Social Work, Neurology, Modeling and Testing. All are  
represented and discussed. As of May 1993 there were  
about 140 individuals from 19 countries subscribed to CSGnet.

ASKING QUESTIONS

Please introduce yourself with a statement of your professional  
interests and background. It will help someone answer if you  
spell out which demonstrations, introductory papers and  
references you have taken the time to digest.

THE CONTROL SYSTEMS GROUP

The CSG is an organization of people in the behavioral, social,  
and life sciences who see the potential in PCT for increased  
understanding in their own fields and for the unification of  
diverse and fragmented specialties.

Annual dues are $45 for full members and $5 for students  
(subsidized).

The tenth North American annual meeting of the CSG will held in  
Durango, Colorado, on the campus of Fort Lewis College. It will  
be held 27-31 July 1994. There will be 7 plenary meetings  
(mornings and evenings), with afternoons, mealtimes, and late  
night free for further discussion or recreation. Full details  
will be available on CSGnet or by mail after April 1, 1994.

The first meeting of the European Control Systems Group (ECSG)  
will be held on 22-26 June 1994, in Aberystwyth, Wales, UK.  
Further information can be obtained from Marcos Rodrigues  
\<[mar@aber.ac.uk](mailto:mar@aber.ac.uk)\>.

Net subscribers find it useful to have thematic collections of  
some of the network discussions, and it enables non-net members  
to keep up with them. Threads from this net are published on a  
quarterly basis in a booklet called the Closed Loop. These  
booklets, distributed to members, are available separately.  
A complimentary copy of Closed Loop will be sent upon request.  
Back issues are available: Volume 1 (4 issues) is $12. Single  
issues of Volume 2, beginning with Jan. 1992, are $6 each.

For membership information and back issues of Closed Loop,  
write: CSG, c/o Mary Powers, 73 Ridge Place CR 510, Durango, CO  
81301-8136.

SUBSCRIBING TO CSGnet

When you subscribe to CSGnet, you get this message,  
CSGINTRO.DOC. But you may have received it from a friend who  
printed it, seen it on a demodisk, or seen it on Usenet. To  
subscribe, send a message as follows: (Internet address followed  
by two message commands, one per line)

&nbsp;&nbsp;LISTSERV@VMD.CSO.UIUC.EDU  
&nbsp;&nbsp;Subscribe CSG-L Lastname, Firstname, Affiliation, City, State.  
&nbsp;&nbsp;help

(Lastname, Firstname, etc is optional commentary, but helpful).  
("help" requests a list of most commonly used commands).  
(The Bitnet address is: LISTSERV@UIUCVMD).  
(This server is not sensitive to upper or lower case letters).

CSGnet can also be accessed via Usenet (NetNews) where it is  
listed as the newsgroup bit.listserv.csg-l.

For more information about accessing CSGnet, contact Gary Cziko,  
the network manager, at G-CZIKO@UIUC.EDU

HOW TO OBTAIN TEXT AND PROGRAM FILES

A number of ASCII documents and binary computer programs are  
available on a fileserver maintained by Bill Silvert. It is  
possible to download all these files via e-mail. If you are on  
internet, it is easiest to obtain binary program files via  
anonymous FTP. If you are on MCI mail, you have read about how  
you can transfer binary files with Kermit or Zmodem protocols.  
(Type help at the MCI mail prompt for directions). But the  
server cannot send binary files over the internet mail network,  
so download uue.scr first, then request the binary files  
uuencoded as ASCII files. The Internet address for the server is  
BIOME.BIO.NS.CA. CSGnet files are kept in the subdirectory  
pub/csg.

To get basic information and a current listing of available  
documents, send a message as follows: (Internet)

Commands: help  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ftp  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;get csg/Index  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end

"help" requests commands and explanations.  
"ftp" asks details on anonymous FTP for internet.  
"get csg/Index" requests the Index for the csg subdirectory.

Pay attention to letter case for commands! DOS is not dos.

As part of the index (of the csg directory), you may be looking  
at:

programs/msdos:  
dem1a.exe 128437 Bill Power's demonstr of perceptual control  
dem2a.exe 123649 Bill Power's modelling of control

documents/forssell:  
uud.scr 53406 ASCII Compile uud.exe w DOS debug Dir @ end.

If you want dem1a.exe (uuencoded) to get a "live" demonstration  
of the phenomenon of control, and the ASCII file uud.scr with  
directions at the end on how to use DOS debug to compile uud.exe  
to decode it, send the following message commands:

uue csg/programs/msdos/dem1a.exe  
get csg/programs/forssell/uud.scr

The uuencoded dem1a.exe will be sent in four parts. Remove  
headers and use an editor to make it into one file (starting  
with table and ending with end) before you use uud.exe to  
restore the file. dem1a.exe is a self-extracting archive file.  
Put it in it's own directory before you execute it. You get  
complete documentation and a running program.

REFERENCES

Here are some selected books, papers and computer programs  
on Perceptual Control Theory (entries preceded by an asterisk are available  
from The Control Systems Group, 460 Black Lick Road,  
Gravel Switch, KY 40328. See order form below).

For a complete list of CSG-related publications, get the file  
biblio.pct from the fileserver as described above.  
Entries preceded by an asterisk in the partial list shown here  
are available from: The Control Systems Group, 460 Black Lick  
Road, Gravel Switch, KY 40328. Price shown includes mailing  
by surface worldwide.

Forssell, Dag C., (1993). Perceptual Control: A Key Management  
Insight." In ENGINEERING MANAGEMENT JOURNAL, 5(4), 17-25.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduction to PCT as an answer to leadership issues.

Forssell, Dag C. (Ed.), (1994). PERCEPTUAL CONTROL THEORY: DOS  
COMPUTER DEMONSTRATIN, TUTORIALS, SIMULATIONS, EXPLANATIONS.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Dag Forssell, Purposeful Leadership, 23903 Via Flamenco,  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Valencia, CA, USA:  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Available on 1.44 MB 3 1/2 inch disk (1 ea) or 1.2 MB  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5 1/4 inch disk (2 ea). May be copied  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;freely. $10 U.S. postpaid by air world wide.

Powers, William T. (1973). BEHAVIOR: THE CONTROL OF  
PERCEPTION. Hawthorne, NY: Aldine DeGruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The basic text.

Petrie, Hugh G. (1981). THE DILEMMA OF INQUIRY AND LEARNING.  
Chicago: University of Chicago Press.

Ford, Edward E. (1989). FREEDOM FROM STRESS. Scottsdale AZ:  
Brandt Publishing.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A self-help book. PCT in a counseling framework.

Hershberger, Wayne. (Ed.). (1989). VOLITIONAL ACTION: CONATION  
AND CONTROL (Advances in Psychology No. 62). NY: North-Holland.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;25 articles (not all PCT)

\*Powers, William T. (1989). LIVING CONTROL SYSTEMS: SELECTED  
PAPERS. Gravel Switch, KY: CSG Books. ($16.50 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously published papers, 1960-1988.

Gibbons, Hugh. (1990). THE DEATH OF JEFFREY STAPLETON:  
EXPLORING THE WAY LAWYERS THINK. Concord, NH: Franklin Pierce  
Law Center.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A text for law students using control theory.

Marken, Richard S. (Ed.). (1990). Purposeful Behavior: The  
control theory approach. AMERICAN BEHAVIORAL SCIENTIST,  
34(1). (Thousand Oaks, CA: Sage Publications)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11 articles on control theory.

McPhail, Clark. (1990). THE MYTH OF THE MADDING CROWD.  
New York: Aldine de Gruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduces control theory to explain group behavior.

\*Robertson, Richard J. and Powers, William T. (Eds.). (1990).  
INTRODUCTION TO MODERN PSYCHOLOGY: THE CONTROL THEORY VIEW.  
Gravel Switch, KY: CSG Book. ($25 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;College-level text.

Runkel, Philip J. (1990). CASTING NETS AND TESTING SPECIMENS.  
New York: Praeger.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;When statistics are appropriate; when models are required.

Richardson, George P. (1991). FEEDBACK THOUGHT IN SOCIAL  
SCIENCE AND SYSTEMS THEORY. Philadelphia: University of  
Pennsylvania Press.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A review of systems thinking, including PCT.

\*Marken, Richard S. (1992). MIND READINGS: EXPERIMENTAL STUDIES  
OF PURPOSE. Gravel Switch, KY: CSG Books. ($18 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Research papers exploring control.

McClelland, Kent. (In press). Perceptual Control and Social Power.  
SOCIOLOGICAL PERSPECTIVES.

McPhail, Clark., Powers, William T., & Tucker, Charles W.  
(1992). Simulating individual and collective action In temporary  
gatherings. SOCIAL SCIENCE COMPUTER REVIEW, 10(1), 1-28.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Computer simulation of control systems in groups.

Cziko, Gary A. (1992). Purposeful behavior as the control  
of perception: Implications for educational research.  
EDUCATIONAL RESEARCHER, 21(9), 10-18, 27. (and...)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduction to PCT and implications for educational  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;research.

Cziko, Gary A. (1992). Perceptual control theory: One threat  
to educational research not (yet?) faced by Amundson,  
Serlin, and Lehrer. EDUCATIONAL RESEARCHER, 21(9), 25-27.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Response to critics of previous article.

\*Powers, William T. (1992). LIVING CONTROL SYSTEMS II: SELECTED  
PAPERS. Gravel Switch, KY: CSG Books. ($22 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously unpublished papers, 1959-1990

Forssell, Dag C., (1993). Perceptual Control: A Key Management  
Insight." In ENGINEERING MANAGEMENT JOURNAL, 5(4), 17-25.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduction to PCT as an answer to leadership issues.

Forssell, Dag C. (Ed.), (1994). PERCEPTUAL CONTROL THEORY: DOS  
COMPUTER DEMONSTRATIN, TUTORIALS, SIMULATIONS, EXPLANATIONS.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Dag Forssell, Purposeful Leadership, 23903 Via Flamenco,  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Valencia, CA, USA:  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.44 MB 3 1/2 inch disk (1 ea) or 1.2 MB  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5 1/4 inch disk (2 ea). May be freely copied  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$10 U.S. by air world wide.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Write: Purposeful Leadership, 23903 Via Flamenco,  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Valencia, CA, USA

> **···**
>
> To: SERVER@BIOME.BIO.NS.CA
> 
> ===========================================================
> 
> CSG BOOK ORDER FORM (from Greg Williams, CSG Book Publishing)
> 
> After so many mentions of CSG books on CSGnet, I should make it  
> easy for all of you folks to order them. Just send the following  
> with your check or money order (U.S. funds ONLY). All prices are  
> postpaid via book post (send extra if you want books fast). If  
> you order five or more books (mixed or matched), you can take  
> off a 20% discount, but I will bill you for actual shipping.
> 
> -----------------------------------------------------------------
> 
> TO: CSG Book Publishing  
> &nbsp;&nbsp;&nbsp;&nbsp;460 Black Lick Rd.  
> &nbsp;&nbsp;&nbsp;&nbsp;Gravel Switch, KY 40328
> 
> PLEASE SEND THE FOLLOWING:
> 
> \_\_\_\_\_ copies of LIVING CONTROL SYSTEMS @ $16.50
> 
> \_\_\_\_\_ copies of LIVING CONTROL SYSTEMS II @ $22.00
> 
> \_\_\_\_\_ copies of INTRODUCTION TO MODERN PSYCHOLOGY @ $25.00
> 
> \_\_\_\_\_ copies of MIND READINGS @ $18.00
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

---

<div class="post-metadata">

**Author:** ![\_Gary\_A\_Cziko](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/3ab097/32.png) [@\_Gary\_A\_Cziko](http://discourse.iapct.org/u/_Gary_A_Cziko)\
**Post date:** [May 3, 1993, 2:50am UTC](http://discourse.iapct.org/t/intro-to-csgnet/376/3 "1993-05-03T02:50:50Z")

</div>

INTRODUCTION TO THE CONTROL SYSTEMS GROUP NETWORK (CSGnet)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AND TO THE CONTROL SYSTEMS GROUP  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepared by Dag Forssell 921118  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Updated 930501 by Gary Cziko

This introduction provides information about:

&nbsp;&nbsp;&nbsp;Our subject: Perceptual Control Theory  
&nbsp;&nbsp;&nbsp;The evolution of the control paradigm  
&nbsp;&nbsp;&nbsp;Demonstrating the Phenomenon of Control  
&nbsp;&nbsp;&nbsp;The purpose of CSGnet  
&nbsp;&nbsp;&nbsp;CSGnet participants  
&nbsp;&nbsp;&nbsp;Asking questions  
&nbsp;&nbsp;&nbsp;The Control Systems Group  
&nbsp;&nbsp;&nbsp;Subscribing to CSGnet  
&nbsp;&nbsp;&nbsp;How to obtain text and program files  
&nbsp;&nbsp;&nbsp;Literature references

OUR SUBJECT: PERCEPTUAL CONTROL THEORY

Here are two introductions by Bill and Mary Powers:

&nbsp;&nbsp;There have been two paradigms in the behavioral sciences since  
&nbsp;&nbsp;the 1600's. One was the idea that events impinging on  
&nbsp;&nbsp;organisms make them behave as they do. The other, which was  
&nbsp;&nbsp;developed in the 1930's, is PERCEPTUAL CONTROL THEORY (PCT).  
&nbsp;&nbsp;Perceptual Control Theory explains how organisms control what  
&nbsp;&nbsp;happens to them. This means all organisms from the amoeba to  
&nbsp;&nbsp;humankind. It explains why one organism can't control another  
&nbsp;&nbsp;without physical violence. It explains why people deprived of  
&nbsp;&nbsp;any major part of their ability to control soon become  
&nbsp;&nbsp;dysfunctional, lose interest in life, pine away and die. It  
&nbsp;&nbsp;explains what a goal is, how goals relate to action, how  
&nbsp;&nbsp;action affects perceptions and how perceptions define the  
&nbsp;&nbsp;reality in which we live and move and have our being.  
&nbsp;&nbsp;Perceptual Control Theory is the first scientific theory that  
&nbsp;&nbsp;can handle all these phenomena within a single, testable  
&nbsp;&nbsp;concept of how living systems work.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;William T. Powers, November 3, 1991

&nbsp;&nbsp;PERCEPTUAL CONTROL THEORY

&nbsp;&nbsp;While the existence of control mechanisms and processes (such  
&nbsp;&nbsp;as feedback) in living systems is generally recognized, the  
&nbsp;&nbsp;implications of control organization go far beyond what is  
&nbsp;&nbsp;generally accepted. We believe that a fundamental  
&nbsp;&nbsp;characteristic of organisms is their ability to control; that  
&nbsp;&nbsp;they are, in fact, living control systems. To distinguish this  
&nbsp;&nbsp;approach from others using some version of control theory but  
&nbsp;&nbsp;forcing it to fit conventional approaches, we call ours  
&nbsp;&nbsp;Perceptual Control Theory, or PCT.

&nbsp;&nbsp;PCT requires a major shift in thinking from the traditional  
&nbsp;&nbsp;approach: that what is controlled is not behavior, but  
&nbsp;&nbsp;perception. Modelling behavior as a dependent variable, as a  
&nbsp;&nbsp;response to stimuli, provides no explanation for the  
&nbsp;&nbsp;phenomenon of achieving consistent ends through varying means,  
&nbsp;&nbsp;and requires an extensive use of statistics to achieve modest  
&nbsp;&nbsp;(to the point of meaningless) correlations. Attempts to model  
&nbsp;&nbsp;behavior as planned and computed output can be demonstrated to  
&nbsp;&nbsp;require levels of precise calculation that are unobtainable in  
&nbsp;&nbsp;a physical system, and impossible in a real environment that  
&nbsp;&nbsp;is changing from one moment to the next. The PCT model views  
&nbsp;&nbsp;behavior as the means by which a perceived state of affairs is  
&nbsp;&nbsp;brought to and maintained at a reference state. This approach  
&nbsp;&nbsp;provides a physically plausible explanation for the  
&nbsp;&nbsp;consistency of outcomes and the variability of means.

&nbsp;&nbsp;The PCT model has been used to simulate phenomena as diverse  
&nbsp;&nbsp;as bacterial chemotaxis, tracking a target, and behavior in  
&nbsp;&nbsp;crowds. In its elaborated form, a hierarchy of perceptual  
&nbsp;&nbsp;control systems (HPCT), it has lent itself to a computer  
&nbsp;&nbsp;simulation of tracking, including learning to track, and to  
&nbsp;&nbsp;new approaches to education, management, and psychotherapy.

&nbsp;&nbsp;Control systems are not new in the life sciences. However,  
&nbsp;&nbsp;numerous misapprehensions exist, passed down from what was  
&nbsp;&nbsp;learned about control theory by non-engineers 40 or 50 years  
&nbsp;&nbsp;ago without further reference to newer developments or  
&nbsp;&nbsp;correction of initial misunderstandings. References in the  
&nbsp;&nbsp;literature to the desirability of positive feedback and the  
&nbsp;&nbsp;assertion that systems with feedback are slower than S-R  
&nbsp;&nbsp;systems are simply false, and concerns about stability are  
&nbsp;&nbsp;unfounded.

&nbsp;&nbsp;The primary barrier to the adoption of PCT concepts is the  
&nbsp;&nbsp;belief - or hope - that control theory can simply be absorbed  
&nbsp;&nbsp;into the mainstream life sciences without disturbing the  
&nbsp;&nbsp;status quo. It is very hard to believe that one's training and  
&nbsp;&nbsp;life work, and that of one's mentors, and their mentors, must  
&nbsp;&nbsp;be fundamentally revised. Therefore, PCT appeals to those who  
&nbsp;&nbsp;feel some dissatisfaction with the status quo, or who are  
&nbsp;&nbsp;attracted to the idea of a generative model with broad  
&nbsp;&nbsp;application throughout the life sciences (plus AI and  
&nbsp;&nbsp;robotics). There are very few people working in PCT research.  
&nbsp;&nbsp;Much of its promise is still simply promise, and it meets  
&nbsp;&nbsp;resistance from all sides. It is frustrating but also  
&nbsp;&nbsp;tremendously exciting to be a part of the group who believe  
&nbsp;&nbsp;that they are participating in the birth of a true science of  
&nbsp;&nbsp;life.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mary Powers, November 1992

THE EVOLUTION OF THE CONTROL PARADIGM

The PCT paradigm originates in 1927, when an engineer named  
Harold Black invented the negative feedback amplifier, which is  
a control device. This invention led to the development of  
purposeful machines. Purposeful machines have built-in intent to  
achieve consistent ends by variable means under changing  
conditions.

The discovery and formalization of the phenomenon of control is  
the first alternative to the cause-effect perspective ever  
proposed in any science.

The first discussion of purposeful machines and people came in  
1943 in a paper called: Behavior, Purpose and Teleology by  
Rosenblueth, Wiener and Bigelow. This paper also argued that  
purpose belongs in science as a real phenomenon in the present.  
Purpose does not mean that somehow the future influences the  
present.

The first specific suggestion on how to use the concept of  
control to understand people came in 1957 in a paper entitled:  
A General Feedback Theory of Human Behavior by McFarland, Powers  
and Clark.

In 1973 William T. (Bill) Powers published a seminal book called  
"Behavior: the Control of Perception," which still is the major  
reference for PCT. See literature below.

This book spells out a complete model of how the human brain and  
nervous system works like a living perceptual control system.  
Our brain can be viewed as a system that controls its own  
perceptions. This view suggests explanations for many previously  
mysterious aspects of how people interact with their world.

Perceptual Control Theory has been accepted by independently  
thinking psychologists, scientists and other interested people.  
The result is that an association has been formed (the Control  
System Group), several books published, this CSGnet set up and  
that at latest count 16 professors are teaching PCT in American  
universities today.

DEMONSTRATING THE PHENOMENON OF CONTROL

The phenomenon of control is largely unrecognized in science  
today. It is not well understood in important aspects even by  
many control engineers. Yet the phenomenon of control, when it  
is recognized and understood, provides a powerful enhancement to  
scientific perspectives.

It is essential to recognize that this phenomenon exists and  
deserves an explanation before any of the discourse on CSGnet  
will make sense.

Please download the introductory demonstration dem1a.exe, which  
is an interactive program and/or rubberbd.txt, which is a text  
telling you how to demonstrate the phenomenon to yourself and a  
friend using only two rubber bands.

THE PURPOSE OF CSGnet:

CSGnet provides a forum for development, use and testing of PCT.

CSGnet PARTICIPANTS

Many interests and backgrounds are represented here. Psychology,  
Sociology, Linguistics, Artificial Intelligence, Robotics,  
Social Work, Neurology, Modeling and Testing. All are  
represented and discussed. As of May 1993 there were  
about 140 individuals from 19 countries subscribed to CSGnet.

ASKING QUESTIONS

Please introduce yourself with a statement of your professional  
interests and background. It will help someone answer if you  
spell out which demonstrations, introductory papers and  
references you have taken the time to digest.

THE CONTROL SYSTEMS GROUP

The CSG is an organization of people in the behavioral, social,  
and life sciences who see the potential in PCT for increased  
understanding in their own fields and for the unification of  
diverse and fragmented specialties.

Annual dues are $45 for full members and $5 for students  
(subsidized).

The next annual meeting will held in Durango, Colorado,  
on the campus of  
Fort Lewis College. In 1993 it will begin in the evening of  
Wednesday, July 28, and end Sunday morning, Aug, 1. There will  
be 7 plenary meetings (mornings and evenings), with afternoons,  
mealtimes, and late night free for further discussion or  
recreation. Full details will be available on the net or by mail  
after April 1, 1993.

The first meeting of the European Control Systems Group (ECSG)  
is planned to take place in late May or early June of 1994 at the  
University of Wales at Aberystwyth. Further information can  
be obtained from Marcos Rodrigues \<[mar@ABER.AC.UK](mailto:mar@ABER.AC.UK)\>.

Net subscribers find it useful to have thematic collections of  
some of the network discussions, and it enables non-net members  
to keep up with them. Threads from this net are published on a  
quarterly basis in a booklet called the Closed Loop. These  
booklets are distributed to members and are available  
separately. A complimentary copy of Closed Loop will be sent  
upon request. Back issues are available: Volume 1 (4 issues) is  
$12. Single issues of Volume 2, beginning with Jan. 1992, are $6  
each.

For membership information and back issues of Closed Loop,  
write: CSG, c/o Mary Powers, 73 Ridge Place CR 510, Durango, CO  
81301-8136.

SUBSCRIBING TO CSGnet

When you subscribe to CSGnet, you get this message,  
CSGINTRO.DOC. But you may have received it from a friend who  
printed it, seen it on a demodisk, or seen it on Usenet. To  
subscribe, send a message as follows: (Internet address followed  
by two message commands, one per line)

&nbsp;&nbsp;LISTSERV@VMD.CSO.UIUC.EDU  
&nbsp;&nbsp;Subscribe CSG-L Lastname, Firstname, Affiliation, City, State.  
&nbsp;&nbsp;help

(Lastname, Firstname, etc is optional commentary, but helpful).  
("help" requests a list of most commonly used commands).  
(The Bitnet address is: LISTSERV@UIUCVMD).  
(This server is not sensitive to upper or lower case letters).

CSGnet can also be accessed via Usenet (NetNews) where it is  
listed as the newsgroup bit.listserv.csg-l.

For more information about accessing CSGnet, contact Gary Cziko,  
the network manager, at G-CZIKO@UIUC.EDU

HOW TO OBTAIN TEXT AND PROGRAM FILES

A number of ASCII documents and binary computer programs are  
available on a fileserver maintained by Bill Silvert. It is  
possible to download all these files via e-mail. If you are on  
internet, it is easiest to obtain binary program files via  
anonymous FTP. If you are on MCI mail, you have read about how  
you can transfer binary files with Kermit or Zmodem protocols.  
(Type help at the MCI mail prompt for directions). But the  
server cannot send binary files over the internet mail network,  
so download uue.scr first, then request the binary files  
uuencoded as ASCII files. The Internet address for the server is  
BIOME.BIO.NS.CA. CSGnet files are kept in the subdirectory  
pub/csg.

To get basic information and a current listing of available  
documents, send a message as follows: (Internet)

Commands: help  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ftp  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;get csg/Index  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end

"help" requests commands and explanations.  
"ftp" asks details on anonymous FTP for internet.  
"get csg/Index" requests the Index for the csg subdirectory.

Pay attention to letter case for commands! DOS is not dos.

As part of the index (of the csg directory), you may be looking  
at:

programs/msdos:  
dem1a.exe 128437 Bill Power's demonstr of perceptual control  
dem2a.exe 123649 Bill Power's modelling of control

documents/forssell:  
uud.scr 53406 ASCII Compile uud.exe w DOS debug Dir @ end.

If you want dem1a.exe (uuencoded) to get a "live" demonstration  
of the phenomenon of control, and the ASCII file uud.scr with  
directions at the end on how to use DOS debug to compile uud.exe  
to decode it, send the following message commands:

uue csg/programs/msdos/dem1a.exe  
get csg/programs/forssell/uud.scr

The uuencoded dem1a.exe will be sent in four parts. Remove  
headers and use an editor to make it into one file (starting  
with table and ending with end) before you use uud.exe to  
restore the file. dem1a.exe is a self-extracting archive file.  
Put it in it's own directory before you execute it. You get  
complete documentation and a running program.

REFERENCES

For a complete list of CSG-related publications, get the file  
biblio.pct from the fileserver as described above.

Here are some selected books and papers on Perceptual Control  
Theory (entries preceded by an asterisk are available from  
The Control Systems Group, 460 Black Lick Road, Gravel Switch,  
KY 40328).

Powers, William T. (1973). \_Behavior: The control of  
perception\_. Hawthorne, NY: Aldine DeGruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The basic text.

Petrie, Hugh G. (1981). \_The dilemma of inquiry and learning\_.  
Chicago: University of Chicago Press.

Ford, Edward E. (1989). \_Freedom from stress\_. Scottsdale AZ:  
Brandt Publishing.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A self-help book. PCT in a counseling framework.

Hershberger, Wayne. (Ed.). (1989). \_Volitional action: Conation  
and control\_ (Advances in Psychology No. 62). NY: North-Holland.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;25 articles (not all PCT)

\*Powers, William T. (1989). \_Living control systems: Selected  
papers\_. Gravel Switch, KY: CSG Books. ($16.50 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously published papers, 1960-1988.

Gibbons, Hugh. (1990). \_The death of Jeffrey Stapleton:  
Exploring the way lawyers think\_. Concord, NH: Franklin Pierce  
Law Center.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A text for law students using control theory.

Marken, Richard S. (Ed.). (1990). Purposeful Behavior: The  
control theory approach. \_American Behavioral Scientist\_,  
\_34\_(1). (Thousand Oaks, CA: Sage Publications)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11 articles on control theory.

McPhail, Clark. (1990). \_The myth of the madding crowd\_.  
New York: Aldine de Gruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduces control theory to explain group behavior.

\*Robertson, Richard J. and Powers, William T. (Eds.). (1990).  
\_Introduction to modern psychology: The control theory view\_.  
Gravel Switch, KY: CSG Book. ($25 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;College-level text.

Runkel, Philip J. (1990). \_Casting nets and testing specimens\_.  
New York: Praeger.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;When statistics are appropriate; when models are required.

Richardson, George P. (1991). \_Feedback thought in social  
science and systems theory\_. Philadelphia: University of  
Pennsylvania Press.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A review of systems thinking, including PCT.

\*Marken, Richard S. (1992). \_Mind readings: Experimental studies  
of purpose\_. Gravel Switch, KY: CSG Books. ($18 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Research papers exploring control.

McClelland, Kent. (1992). \_Perceptual control and sociological  
theory\_. Not yet published. Available from the author,  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Grinnell University, Grinnell, Iowa.

McPhail, Clark., Powers, William T., & Tucker, Charles W.  
(1992). Simulating individual and collective action In temporary  
gatherings. \_Social Science Computer Review\_, \_10\_(1), 1-28.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Computer simulation of control systems in groups.

Cziko, Gary A. (1992). Purposeful behavior as the control  
of perception: Implications for educational research.  
\_Educational Researcher\_, \_21\_(9), 10-18, 27. (and...)

Cziko, Gary A. (1992). Perceptual control theory: One threat  
to educational research not (yet?) faced by Amundson,  
Serlin, and Lehrer. \_Educational Researcher\_, \_21\_(9), 25-27.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduction to PCT and implications for educational  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;research.

\*Powers, William T. (1992). \_Living control systems II: Selected  
papers\_. Gravel Switch, KY: CSG Books. ($22 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously unpublished papers, 1959-1990.

> **···**
>
> To: SERVER@BIOME.BIO.NS.CA.

---

<div class="post-metadata">

**Author:** ![\_Gary\_A\_Cziko](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/3ab097/32.png) [@\_Gary\_A\_Cziko](http://discourse.iapct.org/u/_Gary_A_Cziko)\
**Post date:** [May 2, 1994, 2:10am UTC](http://discourse.iapct.org/t/intro-to-csgnet/376/4 "1994-05-02T02:10:48Z")

</div>

INTRODUCTION TO THE CONTROL SYSTEMS GROUP (CSG)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AND THE CONTROL SYSTEMS GROUP NETWORK (CSGnet)

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepared by Dag Forssell with Gary Cziko  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Updated 1994.04.29

This introduction provides information about:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Our Subject: Perceptual Control Theory  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Evolution of the Control Paradigm  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Demonstrating the Phenomenon of Control  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Purpose of CSGnet  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;CSGnet Participants  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Asking Questions  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Control Systems Group  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Accessing and Subscribing to CSGnet  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;How to Obtain Text and Program Files  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;References  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Order Forms

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;OUR SUBJECT: PERCEPTUAL CONTROL THEORY

Here are two introductions by Bill and Mary Powers:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\* \* \* \* \* \* \* \*

There have been two paradigms in the behavioral sciences since  
the 1600's. One was the idea that events impinging on organisms  
make them behave as they do. The other, which was developed in  
the 1930's, is PERCEPTUAL CONTROL THEORY (PCT). Perceptual  
Control Theory explains how organisms control what happens to  
them. This means all organisms from the amoeba to humankind. It  
explains why one organism can't control another without physical  
violence. It explains why people deprived of any major part of  
their ability to control soon become dysfunctional, lose interest  
in life, pine away and die. It explains what a goal is, how  
goals relate to action, how action affects perceptions and how  
perceptions define the reality in which we live and move and have  
our being. Perceptual Control Theory is the first scientific  
theory that can handle all these phenomena within a single,  
testable concept of how living systems work.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;William T. Powers, November 3, 1991

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\* \* \* \* \* \* \* \*

While the existence of control mechanisms and processes (such as  
feedback) in living systems is generally recognized, the  
implications of control organization go far beyond what is  
generally accepted. We believe that a fundamental characteristic  
of organisms is their ability to control; that they are, in fact,  
living control systems. To distinguish this approach from others  
using some version of control theory but forcing it to fit  
conventional approaches, we call ours Perceptual Control Theory,  
or PCT.

PCT requires a major shift in thinking from the traditional  
approach: that what is controlled is not behavior, but  
perception. Modelling behavior as a dependent variable, as a  
response to stimuli, provides no explanation for the phenomenon  
of achieving consistent ends through varying means, and requires  
an extensive use of statistics to achieve modest (to the point of  
meaningless) correlations. Attempts to model behavior as planned  
and computed output can be demonstrated to require levels of  
precise calculation that are unobtainable in a physical system,  
and impossible in a real environment that is changing from one  
moment to the next. The PCT model views behavior as the means by  
which a perceived state of affairs is brought to and maintained  
at a reference state. This approach provides a physically  
plausible explanation for the consistency of outcomes and the  
variability of means.

The PCT model has been used to simulate phenomena as diverse as  
bacterial chemotaxis, tracking a target, and behavior in crowds.  
In its elaborated form, a hierarchy of perceptual control systems  
(HPCT), it has lent itself to a computer simulation of tracking,  
including learning to track, and to new approaches to education,  
management, and psychotherapy.

Control systems are not new in the life sciences. However,  
numerous misapprehensions exist, passed down from what was  
learned about control theory by non-engineers 40 or 50 years ago  
without further reference to newer developments or correction of  
initial misunderstandings. References in the literature to the  
desirability of positive feedback and the assertion that systems  
with feedback are slower than S-R systems are simply false, and  
concerns about stability are unfounded.

The primary barrier to the adoption of PCT concepts is the belief-  
-or hope--that control theory can simply be absorbed into the  
mainstream life sciences without disturbing the status quo. It  
is very hard to believe that one's training and life work, and  
that of one's mentors, and their mentors, must be fundamentally  
revised. Therefore, PCT appeals to those who feel some  
dissatisfaction with the status quo, or who are attracted to the  
idea of a generative model with broad application throughout the  
life sciences (plus AI and robotics). There are very few people  
working in PCT research. Much of its promise is still simply  
promise, and it meets resistance from all sides. It is  
frustrating but also tremendously exciting to be a part of the  
group who believe that they are participating in the birth of a  
true science of life.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mary Powers, November 1992

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\* \* \* \* \* \* \* \*

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;THE EVOLUTION OF THE CONTROL PARADIGM

The PCT paradigm originates in 1927, when an engineer named  
Harold Black completed the technical analysis of closed loop  
control systems. He was working with the negative feedback  
amplifier, which is a control device. This led to a new  
engineering discipline and the development of many purposeful  
machines. Purposeful machines have built-in intent to achieve  
consistent ends by variable means under changing conditions.

The explanation for the phenomenon of control is the first  
alternative to the linear cause-effect perspective ever  
proposed in any science.

The first discussion of purposeful machines and people came in  
1943 in a paper called: Behavior, Purpose and Teleology by  
Rosenblueth, Wiener and Bigelow. This paper also argued that  
purpose belongs in science as a real phenomenon in the present.  
Purpose does not mean that somehow the future influences the  
present.

The first specific suggestion on how to use the concept of  
control to understand people came in 1957 in a paper entitled: A  
General Feedback Theory of Human Behavior by McFarland, Powers  
and Clark.

In 1973 William T. (Bill) Powers published a seminal book called  
"Behavior: the Control of Perception," which still is the major  
reference for PCT. See literature below.

This book spells out a complete model of how the human brain and  
nervous system works like a living perceptual control system. Our  
brain can be viewed as a system that controls its own  
perceptions. This view suggests explanations for many previously  
mysterious aspects of how people interact with their world.

Perceptual Control Theory has been accepted by independently  
thinking psychologists, scientists and other interested people.  
The result is that an association has been formed (the Control  
System Group), several books published, this CSGnet set up and  
that at latest count 16 professors are teaching PCT in American  
universities today.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;DEMONSTRATING THE PHENOMENON OF CONTROL

The phenomenon of control is largely unrecognized in science  
today. It is not well understood in important aspects even by  
many control engineers. Yet the phenomenon of control, when it is  
recognized and understood, provides a powerful enhancement to  
scientific perspectives.

It is essential to recognize that this phenomenon exists and  
deserves an explanation before any of the discourse on CSGnet  
will make sense.

Please download the introductory demonstration dem1a.exe, which  
is an interactive program and/or rubberbd.txt, which is a text  
telling you how to demonstrate the phenomenon to yourself and a  
friend using only two rubber bands.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;THE PURPOSE OF CSGnet

CSGnet provides a forum for development, use and testing of PCT.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;CSGnet PARTICIPANTS

Many interests and backgrounds are represented here. Psychology,  
Sociology, Linguistics, Artificial Intelligence, Robotics, Social  
Work, Neurology, Modeling and Testing. All are represented and  
discussed. As of May 1993 there were about 140 individuals from  
19 countries subscribed to CSGnet.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ASKING QUESTIONS

Please introduce yourself with a statement of your professional  
interests and background. It will help someone answer if you  
spell out which demonstrations, introductory papers and  
references you have taken the time to digest.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;THE CONTROL SYSTEMS GROUP

The CSG is an organization of people in the behavioral, social,  
and life sciences who see the potential in PCT for increased  
understanding in their own fields and for the unification of  
diverse and fragmented specialties.

Annual dues are $45 for full members and $5 for students  
(subsidized).

The tenth North American annual meeting of the CSG will held in  
Durango, Colorado, on the campus of Fort Lewis College. It will  
be held 27-31 July 1994. There will be 7 plenary meetings  
(mornings and evenings), with afternoons, mealtimes, and late  
night free for further discussion or recreation. Full details  
will be available on CSGnet or by mail after April 1, 1994. The  
first meeting of the European Control Systems Group (ECSG) will  
be held on 22-26 June 1994, in Aberystwyth, Wales, UK. Further  
information can be obtained from Marcos Rodrigues  
\<[mar@aber.ac.uk](mailto:mar@aber.ac.uk)\>.

Net subscribers find it useful to have thematic collections of  
some of the network discussions, and it enables non-net members  
to keep up with them. Threads from this net are published on a  
quarterly basis in a booklet called the Closed Loop. These  
booklets, distributed to members, are available separately. A  
complimentary copy of Closed Loop will be sent upon request.  
Back issues are available: Volume 1 (4 issues) is $12. Single  
issues of Volume 2, beginning with Jan. 1992, are $6 each.

For membership information and back issues of Closed Loop, write:  
CSG, c/o Mary Powers, 73 Ridge Place CR 510, Durango, CO 81301-  
8136 or send e-mail to \<POWERS\_W%FLC@VAXF.COLORADO.EDU\>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ACCESSING AND SUBSCRIBING TO CSGnet

CSGnet can also be accessed via Usenet where it is listed as the  
newsgroup "bit.listserv.csg-l."

To subscribe to the listserv version of CSGnet, send a message as  
follows to \<LISTSERV@VMD.CSO.UIUC.EDU\>:

Subscribe CSG-L Lastname, Firstname, Affiliation, Location  
Help

"Lastname, Firstname," etc is optional but helpful. "Help"  
requests a list of most commonly used commands. The Bitnet  
address for the list server is LISTSERV@UIUCVMD. This server is  
not case sensitive.

Messages to the entire CSGnet community should be addressed to  
\<CSG-L@VMD.CSO.UIUC.EDU\> (Internet) or \<CSG-L@UIUCVMD\> (Bitnet).

For more information about accessing CSGnet, contact Gary Cziko,  
the network manager, at \<G-CZIKO@UIUC.EDU\>.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;HOW TO OBTAIN TEXT AND PROGRAM FILES

A number of ASCII documents and MS-DOS and Macintosh computer  
programs are available on a fileserver maintained by Bill  
Silvert. These files can be obtained via anonymous FTP, Gopher,  
World Wide Web, and e-mail.

ANONYMOUS FTP

For anonymous FTP access, connect to biome.bio.ns.ca, logon as  
anonymous, giving your e-mail address as your password. The CSG  
files can be found in the directory pub/csg.

Two programs of particular interest for MS-DOS machines can be  
found in the directory pub/csg/programs/msdos. The file names  
are dem1a.exe and dem2a.exe. These are self-extracting files  
which provide Bill Powers's demonstrations of the phenomenon of  
control and the perceptual control theory model of behavior.  
Also of interest is the complete PCT bibliography complied by  
Greg Williams. This file can be found in the directory  
pub/csg/documents as biblio.pct.

A file in MS-DOS zip format containing the above-mentioned demo  
programs as well as others compiled by Dag Forssell is available  
as pub/csg/programs/msdos/forssell.zip.

GOPHER AND WORLD WIDE WEB

For Gopher access, point your Gopher at biome.bio.ns.ca. This  
can usually done by following the following path (although the  
first four steps below may differ depending on how you access  
Gopher):

-\> Other Gopher and Information Servers  
-\> North America  
-\> Canada  
-\> Bedford Institute of Oceanography (Canada)  
-\> Organizations  
-\> Control Systems Group

The exact link is:

Type=1  
Name=Control Systems Group  
Path=1/FTP/pub/csg  
Host=biome.bio.ns.ca  
Port=70  
URL: gopher://biome.bio.ns.ca:70/11/FTP/pub/csg

which can also be used with World Wide Web.

E-MAIL

Document files and uuencoded versions of program files can also  
be obtained via e-mail. Here are some basic commands for  
obtaining files and information:

Commands:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;help  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;get pub/csg/00index

"help" requests commands and explanations  
"get pub/csg/00index" requests index for the csg subdirectory.

Pay attention to letter case for commands! DOS is not dos.  
The pub/csg/00index you receive in response will show additional  
directories and enable you to send messages to find out what is  
available in your area of interest.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;REFERENCES

Here are some selected books, papers and computer programs on  
Perceptual Control Theory. For a complete list of CSG-related  
publications, get the file biblio.pct from the fileserver as  
described above. A PCT RESOURCE GUIDE with more detailed  
information is available by sending a self-addressed, stamped  
envelope (or address and two reply coupons for international  
postage) to Purposeful Leadership. (Address below). All prices as  
of April, 1994.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\* \* \* \* \* \* \* \*

Cziko, Gary A. (1992). Purposeful behavior as the control of  
&nbsp;&nbsp;perception: Implications for educational research. EDUCATIONAL  
&nbsp;&nbsp;RESEARCHER, 21(9), 10-18, 27. Back issue $9. Publication  
&nbsp;&nbsp;office: Washington DC. (202) 223-9485.

Cziko, Gary A. (1992). Perceptual control theory: One threat to  
&nbsp;&nbsp;educational research not (yet?) faced by Amundson, Serlin, and  
&nbsp;&nbsp;Lehrer. EDUCATIONAL RESEARCHER, 21(9), 25-27. Response to  
&nbsp;&nbsp;critics of previous article.

Ford, Edward E. (1989). FREEDOM FROM STRESS. Scottsdale AZ:  
&nbsp;&nbsp;Brandt Publishing. PCT in a comprehensive counseling story.  
&nbsp;&nbsp;See order form.

Ford, Edward E. (1987). LOVE GUARANTEED. Scottsdale AZ:  
&nbsp;&nbsp;Brandt Publishing. PCT in marriage counseling. See order form.

Forssell, Dag C., (1993). Perceptual Control: A New Management  
&nbsp;&nbsp;Insight." In ENGINEERING MANAGEMENT JOURNAL, 5(4), 17-25.  
&nbsp;&nbsp;See order form: introduction book.

Forssell, Dag C. (Ed.), (1994). PERCEPTUAL CONTROL THEORY: DOS  
&nbsp;&nbsp;COMPUTER DEMONSTRATION, TUTORIALS, SIMULATIONS, EXPLANATIONS.  
&nbsp;&nbsp;1.44 MB 3 1/2" disk (1 ea) or 1.2 MB 5 1/4" disk (2 ea). May  
&nbsp;&nbsp;be freely copied. See order form.

Forssell, Dag C., (1994). PERCEPTUAL CONTROL: USEFUL MANAGEMENT  
&nbsp;&nbsp;INSIGHT. Structure and evidence for HPCT, with application  
&nbsp;&nbsp;to conflict resolution. See order form: Introduction book.

Forssell, Dag C., (1994). PSYCHOLOGICAL THEORY: THE ACHILLES'  
&nbsp;&nbsp;HEEL OF TQM. ENGINEERING MANAGEMENT JOURNAL. Defining useful  
&nbsp;&nbsp;theory and assessing TQM. See order form: Introduction book.

Gibbons, Hugh. (1990). THE DEATH OF JEFFREY STAPLETON: EXPLORING  
&nbsp;&nbsp;THE WAY LAWYERS THINK. Concord, NH: Franklin Pierce Law Center.  
&nbsp;&nbsp;Using PCT to explain how lawyers think. Send $10 to  
&nbsp;&nbsp;Hugh Gibbons, Professor, Franklin Pierce Law Center,  
&nbsp;&nbsp;Concord, NH, 03301.

Hershberger, Wayne. (Ed.). (1989). VOLITIONAL ACTION: CONATION  
&nbsp;&nbsp;AND CONTROL (Advances in Psychology No. 62). NY: North-Holland  
&nbsp;&nbsp;(Elsevier). 25 articles (not all PCT). See order form.

Marken, Richard S. (Ed.). (1990). Purposeful Behavior: The  
&nbsp;&nbsp;control theory approach. AMERICAN BEHAVIORAL SCIENTIST, 34(1).  
&nbsp;&nbsp;(Thousand Oaks, CA: Sage Publications) 11 articles on  
&nbsp;&nbsp;control theory. See order form.

Marken, Richard S. (1992). MIND READINGS: EXPERIMENTAL STUDIES  
&nbsp;&nbsp;OF PURPOSE. Gravel Switch, KY: CSG Books. ($18 postpaid)  
&nbsp;&nbsp;Research papers exploring control. See order form.

McClelland, Kent. (In press). Perceptual Control and Social  
&nbsp;&nbsp;Power. SOCIOLOGICAL PERSPECTIVES. 24 pages. In press: December  
&nbsp;&nbsp;1994. Send $5 to: Kent McClelland, Professor, Dept. of  
&nbsp;&nbsp;Sociology, Grinnell College, Grinnell, IA, 50112.

McPhail, Clark. (1990). THE MYTH OF THE MADDING CROWD. New York:  
&nbsp;&nbsp;Aldine de Gruyter. Introduces control theory to explain group  
&nbsp;&nbsp;behavior. See order form.

McPhail, Clark., Powers, William T., & Tucker, Charles W. (1992).  
&nbsp;&nbsp;Simulating individual and collective action In temporary  
&nbsp;&nbsp;gatherings. SOCIAL SCIENCE COMPUTER REVIEW, 10(1), 1-28.  
&nbsp;&nbsp;Computer simulation of control systems in groups. Duke  
&nbsp;&nbsp;University Press: Box 90660, Durham, NC. (919) 687-3600.

Petrie, Hugh G. (1981). THE DILEMMA OF INQUIRY AND LEARNING.  
&nbsp;&nbsp;Chicago: University of Chicago Press. Out of print.

Powers, William T. (1973). BEHAVIOR: THE CONTROL OF PERCEPTION.  
&nbsp;&nbsp;Hawthorne, NY: Aldine DeGruyter. The basic text. See order form.

Powers, William T. (1989). LIVING CONTROL SYSTEMS: SELECTED  
&nbsp;&nbsp;PAPERS. Gravel Switch, KY: CSG Books. Previously published  
&nbsp;&nbsp;papers, 1960-1988. See order form.

Powers, William T. (1992). LIVING CONTROL SYSTEMS II: SELECTED  
&nbsp;&nbsp;PAPERS. Gravel Switch, KY: CSG Books.Previously unpublished  
&nbsp;&nbsp;papers, 1959-1990. See order form.

Richardson, George P. (1991). FEEDBACK THOUGHT IN SOCIAL SCIENCE  
&nbsp;&nbsp;AND SYSTEMS THEORY. A review of systems thinking, including PCT.  
&nbsp;&nbsp;(Paperback $19.95) ISBN 0-8122-1332-7 University of  
&nbsp;&nbsp;Pennsylvania Press. (800) 445-9880.

Robertson, Richard J. and Powers, William T. (Eds.). (1990).  
&nbsp;&nbsp;INTRODUCTION TO MODERN PSYCHOLOGY: THE CONTROL THEORY VIEW.  
&nbsp;&nbsp;Gravel Switch, KY: CSG Book. College-level text. See order form.

Runkel, Philip J. (1990). CASTING NETS AND TESTING SPECIMENS.  
&nbsp;&nbsp;When statistics are appropriate; when models are required.  
&nbsp;&nbsp;With explanation of PCT. Clothbound, $45. Order code: C3533  
&nbsp;&nbsp;Praeger Publishers, P.O. Box 5007, Westport, CT 06881  
&nbsp;&nbsp;Phone: (800) 225-5800, (203) 226-3571, Fax (203) 222-1502.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\* \* \* \* \* \* \* \*

Order forms copied from the PCT resource guide:

> **···**
>
> To: SERVER@BIOME.BIO.NS.CA  
> -----------------------------------------------------------------------  
> CSG Book Publishing: Greg Williams Phone: (606) 332-7606  
> 460 Black Lick Road, Gravel Switch, KY 40328 USA
> 
> \_\_\_ ea INTRODUCTION TO MODERN PSYCHOLOGY @ $25.00 \_\_\_\_\_\_\_  
> \_\_\_ ea LIVING CONTROL SYSTEMS @ $16.50 \_\_\_\_\_\_\_  
> \_\_\_ ea LIVING CONTROL SYSTEMS II @ $22.00 \_\_\_\_\_\_\_  
> \_\_\_ ea MIND READINGS @ $18.00 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Kentucky residents please add sales tax Tax \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Shipping & Handling (world wide) per order \_5.00\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepaid: Check, money order total \_\_\_\_\_\_\_
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Phone(\_\_\_\_\_\_)\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> -----------------------------------------------------------------------  
> Purposeful Leadership: Dag Forssell Phone: (805) 254-1195  
> 23903 Via Flamenco, Valencia, CA 91355-2808 USA Fax: (805) 254-7956
> 
> \_\_\_ ea Articles & Program Info. Introduction book @ $20.00 \_\_\_\_\_\_\_  
> \_\_\_ ea PCTdemos. DOS program disk \_\_ 31/2" \_\_5 1/4" @ $10.00 \_\_\_\_\_\_\_  
> \_\_\_ ea Rubber Band Demo. Video & Script 63 minutes @ $20.00 \_\_\_\_\_\_\_  
> \_\_\_ ea PCT supports TQM. Video 117 minutes @ $20.00 \_\_\_\_\_\_\_  
> \_\_\_ ea Deming-Observ., Interpret., Comment. Booklet @ $10.00 \_\_\_\_\_\_\_  
> \_\_\_ ea Freedom From Stress. Book by Ed Ford @ $10.00 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;California residents please add sales tax Tax \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Shipping & Handling (world wide) per order \_5.00\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepaid: Check, money order total \_\_\_\_\_\_\_
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Phone(\_\_\_\_\_\_)\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> -----------------------------------------------------------------------  
> Brandt Publishing: Edward E. Ford Phone & Fax: (602) 991-4860  
> 10209 North 56th Street, Scottsdale, AZ 85253-1130 USA
> 
> \_\_\_ ea Freedom From Stress, Book @ $10.00 \_\_\_\_\_\_\_  
> \_\_\_ ea Love Guaranteed, Book @ $ 9.00 \_\_\_\_\_\_\_  
> \_\_\_ ea Love Guaranteed, Video @ $20.00 \_\_\_\_\_\_\_  
> \_\_\_ ea Discipline for Home and School, Book (July 94) @ $10.00 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Arizona residents please add sales tax Tax \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Shipping & Handling (world wide) per order \_5.00\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepaid: Check, money order total \_\_\_\_\_\_\_
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Phone(\_\_\_\_\_\_)\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> -----------------------------------------------------------------------
> 
> Journal Marketing, Sage Publications Phone orders: (805) 499-0721  
> 2455 Teller Rd, Newbury Park, CA 91320 USA Fax: (805) 499-0871
> 
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;American Behavioral Scientist, Volume 34, Number 1 Sept/Oct 1990  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Stock number 201238 Richard S. Marken, Editor  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Purposeful Behavior; The Control Theory Approach,  
> \_\_\_ ea Price for individuals and companies: @ $11.20 \_\_\_\_\_\_\_  
> \_\_\_ ea Price for institutions and libraries: @ $22.40 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;California residents add sales tax 7.25% Tax \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Shipping & Handling (world wide) per order \_2.00\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepaid: Check, money order, credit cards total \_\_\_\_\_\_\_
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Phone(\_\_\_\_\_\_)\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> -----------------------------------------------------------------------
> 
> Elsevier Science Phone orders: (212) 633-3650  
> 655 Avenue of the Americas New York, NY 10010 USA Fax: (212) 633-3680
> 
> \_\_\_ ea Volitional Action, Conation and Control, W.A. Hershberger, Ed.  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ISBN: 0-444-88318-5 @ $155.50 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;New York residents add sales tax Tax \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Shipping included with prepaid orders \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Check, money order, credit cards, P.O's Total \_\_\_\_\_\_\_
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Phone(\_\_\_\_\_\_)\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> -----------------------------------------------------------------------
> 
> Aldine de Gruyter Phone orders: (914) 747-0110  
> 200 Saw Mill River Road, Hawthorne, NY 10532 USA Fax: (914) 747-1326
> 
> \_\_\_ ea Behavior: The Control of Perception by William T. Powers  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Clothbound ISBN 0-202-25113-6 @ $41.95 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The Myth of the Madding Crowd by Clark McPhail  
> \_\_\_ ea Clothbound ISBN 0-202-30424-8 @ $47.95 \_\_\_\_\_\_\_  
> \_\_\_ ea Paperbound ISBN 0-202-30375-6 @ $24.95 \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;New York residents add sales tax Tax \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Shipping: $4 for first book, $1 per additional \_\_\_\_\_\_\_  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Check, money order, credit cards Total \_\_\_\_\_\_\_
> 
> NAME \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_Phone(\_\_\_\_\_\_)\_\_\_\_\_\_\_-\_\_\_\_\_\_\_\_\_\_
> 
> ADDRESS \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
> 
> -----------------------------------------------------------------------

---

<div class="post-metadata">

**Author:** ![\_Gary\_A\_Cziko](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/_/3ab097/32.png) [@\_Gary\_A\_Cziko](http://discourse.iapct.org/u/_Gary_A_Cziko)\
**Post date:** [December 2, 1992, 6:39pm UTC](http://discourse.iapct.org/t/intro-to-csgnet/376/5 "1992-12-02T18:39:56Z")

</div>

INTRODUCTION TO THE CONTROL SYSTEMS GROUP NETWORK (CSGnet)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;AND TO THE CONTROL SYSTEMS GROUP  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepared by Dag Forssell 921118.

This introduction provides information about:

&nbsp;&nbsp;&nbsp;Our subject: Perceptual Control Theory  
&nbsp;&nbsp;&nbsp;The evolution of the control paradigm  
&nbsp;&nbsp;&nbsp;Demonstrating the Phenomenon of Control  
&nbsp;&nbsp;&nbsp;The purpose of CSGnet  
&nbsp;&nbsp;&nbsp;CSGnet participants  
&nbsp;&nbsp;&nbsp;Asking questions  
&nbsp;&nbsp;&nbsp;The Control Systems Group  
&nbsp;&nbsp;&nbsp;Subscribing to CSGnet  
&nbsp;&nbsp;&nbsp;How to obtain text and program files  
&nbsp;&nbsp;&nbsp;Literature references

OUR SUBJECT: PERCEPTUAL CONTROL THEORY

Here are two introductions by Bill and Mary Powers:

&nbsp;&nbsp;There have been two paradigms in the behavioral sciences since  
&nbsp;&nbsp;the 1600's. One was the idea that events impinging on  
&nbsp;&nbsp;organisms make them behave as they do. The other, which was  
&nbsp;&nbsp;developed in the 1930's, is PERCEPTUAL CONTROL THEORY (PCT).  
&nbsp;&nbsp;Perceptual Control Theory explains how organisms control what  
&nbsp;&nbsp;happens to them. This means all organisms from the amoeba to  
&nbsp;&nbsp;humankind. It explains why one organism can't control another  
&nbsp;&nbsp;without physical violence. It explains why people deprived of  
&nbsp;&nbsp;any major part of their ability to control soon become  
&nbsp;&nbsp;dysfunctional, lose interest in life, pine away and die. It  
&nbsp;&nbsp;explains what a goal is, how goals relate to action, how  
&nbsp;&nbsp;action affects perceptions and how perceptions define the  
&nbsp;&nbsp;reality in which we live and move and have our being.  
&nbsp;&nbsp;Perceptual Control Theory is the first scientific theory that  
&nbsp;&nbsp;can handle all these phenomena within a single, testable  
&nbsp;&nbsp;concept of how living systems work.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;William T. Powers, November 3, 1991

&nbsp;&nbsp;PERCEPTUAL CONTROL THEORY

&nbsp;&nbsp;While the existence of control mechanisms and processes (such  
&nbsp;&nbsp;as feedback) in living systems is generally recognized, the  
&nbsp;&nbsp;implications of control organization go far beyond what is  
&nbsp;&nbsp;generally accepted. We believe that a fundamental  
&nbsp;&nbsp;characteristic of organisms is their ability to control; that  
&nbsp;&nbsp;they are, in fact, living control systems. To distinguish this  
&nbsp;&nbsp;approach from others using some version of control theory but  
&nbsp;&nbsp;forcing it to fit conventional approaches, we call ours  
&nbsp;&nbsp;Perceptual Control Theory, or PCT.

&nbsp;&nbsp;PCT requires a major shift in thinking from the traditional  
&nbsp;&nbsp;approach: that what is controlled is not behavior, but  
&nbsp;&nbsp;perception. Modelling behavior as a dependent variable, as a  
&nbsp;&nbsp;response to stimuli, provides no explanation for the  
&nbsp;&nbsp;phenomenon of achieving consistent ends through varying means,  
&nbsp;&nbsp;and requires an extensive use of statistics to achieve modest  
&nbsp;&nbsp;(to the point of meaningless) correlations. Attempts to model  
&nbsp;&nbsp;behavior as planned and computed output can be demonstrated to  
&nbsp;&nbsp;require levels of precise calculation that are unobtainable in  
&nbsp;&nbsp;a physical system, and impossible in a real environment that  
&nbsp;&nbsp;is changing from one moment to the next. The PCT model views  
&nbsp;&nbsp;behavior as the means by which a perceived state of affairs is  
&nbsp;&nbsp;brought to and maintained at a reference state. This approach  
&nbsp;&nbsp;provides a physically plausible explanation for the  
&nbsp;&nbsp;consistency of outcomes and the variability of means.

&nbsp;&nbsp;The PCT model has been used to simulate phenomena as diverse  
&nbsp;&nbsp;as bacterial chemotaxis, tracking a target, and behavior in  
&nbsp;&nbsp;crowds. In its elaborated form, a hierarchy of perceptual  
&nbsp;&nbsp;control systems (HPCT), it has lent itself to a computer  
&nbsp;&nbsp;simulation of tracking, including learning to track, and to  
&nbsp;&nbsp;new approaches to education, management, and psychotherapy.

&nbsp;&nbsp;Control systems are not new in the life sciences. However,  
&nbsp;&nbsp;numerous misapprehensions exist, passed down from what was  
&nbsp;&nbsp;learned about control theory by non-engineers 40 or 50 years  
&nbsp;&nbsp;ago without further reference to newer developments or  
&nbsp;&nbsp;correction of initial misunderstandings. References in the  
&nbsp;&nbsp;literature to the desirability of positive feedback and the  
&nbsp;&nbsp;assertion that systems with feedback are slower than S-R  
&nbsp;&nbsp;systems are simply false, and concerns about stability are  
&nbsp;&nbsp;unfounded.

&nbsp;&nbsp;The primary barrier to the adoption of PCT concepts is the  
&nbsp;&nbsp;belief - or hope - that control theory can simply be absorbed  
&nbsp;&nbsp;into the mainstream life sciences without disturbing the  
&nbsp;&nbsp;status quo. It is very hard to believe that one's training and  
&nbsp;&nbsp;life work, and that of one's mentors, and their mentors, must  
&nbsp;&nbsp;be fundamentally revised. Therefore, PCT appeals to those who  
&nbsp;&nbsp;feel some dissatisfaction with the status quo, or who are  
&nbsp;&nbsp;attracted to the idea of a generative model with broad  
&nbsp;&nbsp;application throughout the life sciences (plus AI and  
&nbsp;&nbsp;robotics). There are very few people working in PCT research.  
&nbsp;&nbsp;Much of its promise is still simply promise, and it meets  
&nbsp;&nbsp;resistance from all sides. It is frustrating but also  
&nbsp;&nbsp;tremendously exciting to be a part of the group who believe  
&nbsp;&nbsp;that they are participating in the birth of a true science of  
&nbsp;&nbsp;life.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mary Powers, November 1992

THE EVOLUTION OF THE CONTROL PARADIGM

The PCT paradigm originates in 1927, when an engineer named  
Harold Black invented the negative feedback amplifier, which is  
a control device. This invention led to the development of  
purposeful machines. Purposeful machines have built-in intent to  
achieve consistent ends by variable means under changing  
conditions.

The discovery and formalization of the phenomenon of control is  
the first alternative to the cause-effect perspective ever  
proposed in any science.

The first discussion of purposeful machines and people came in  
1943 in a paper called: Behavior, Purpose and Teleology by  
Rosenblueth, Wiener and Bigelow. This paper also argued that  
purpose belongs in science as a real phenomenon in the present.  
Purpose does not mean that somehow the future influences the  
present.

The first specific suggestion on how to use the concept of  
control to understand people came in 1957 in a paper entitled:  
A General Feedback Theory of Human Behavior by McFarland, Powers  
and Clark.

In 1973 William T. (Bill) Powers published a seminal book called  
"Behavior: the Control of Perception," which still is the major  
reference for PCT. See literature below.

This book spells out a complete model of how the human brain and  
nervous system works like a living perceptual control system.  
Our brain can be viewed as a system that controls its own  
perceptions. This view suggests explanations for many previously  
mysterious aspects of how people interact with their world.

Perceptual Control Theory has been accepted by independently  
thinking psychologists, scientists and other interested people.  
The result is that an association has been formed (the Control  
System Group), several books published, this CSGnet set up and  
that at latest count 16 professors are teaching PCT in American  
universities today.

DEMONSTRATING THE PHENOMENON OF CONTROL

The phenomenon of control is largely unrecognized in science  
today. It is not well understood in important aspects even by  
many control engineers. Yet the phenomenon of control, when it  
is recognized and understood, provides a powerful enhancement to  
scientific perspectives.

It is essential to recognize that this phenomenon exists and  
deserves an explanation before any of the discourse on CSGnet  
will make sense.

Please download the introductory demonstration dem1a.exe, which  
is an interactive program and/or rubberbd.txt, which is a text  
telling you how to demonstrate the phenomenon to yourself and a  
friend using only two rubber bands.

THE PURPOSE OF CSGnet:

CSGnet provides a forum for development, use and testing of PCT.

CSGnet PARTICIPANTS

Many interests and backgrounds are represented here. Psychology,  
Sociology, Linguistics, Artificial Intelligence, Robotics,  
Social Work, Neurology, Modeling and Testing. All are  
represented and discussed. As of December 1992 there were  
over 130 individuals from 18 countries subscribed to CSGnet.

ASKING QUESTIONS

Please introduce yourself with a statement of your professional  
interests and background. It will help someone answer if you  
spell out which demonstrations, introductory papers and  
references you have taken the time to digest.

THE CONTROL SYSTEMS GROUP

The CSG is an organization of people in the behavioral, social,  
and life sciences who see the potential in PCT for increased  
understanding in their own fields and for the unification of  
diverse and fragmented specialties.

Annual dues are $45 for full members and $5 for students  
(subsidized).

An annual meeting is held in Durango, Colorado, on the campus of  
Fort Lewis College. In 1993 it will begin in the evening of  
Wednesday, July 28, and end Sunday morning, Aug, 1. There will  
be 7 plenary meetings (mornings and evenings), with afternoons,  
mealtimes, and late night free for further discussion or  
recreation. Full details will be available on the net or by mail  
after April 1, 1993.

Net subscribers find it useful to have thematic collections of  
some of the network discussions, and it enables non-net members  
to keep up with them. Threads from this net are published on a  
quarterly basis in a booklet called the Closed Loop. These  
booklets are distributed to members and are available  
separately. A complimentary copy of Closed Loop will be sent  
upon request. Back issues are available: Volume 1 (4 issues) is  
$12. Single issues of Volume 2, beginning with Jan. 1992, are $6  
each.

For membership information and back issues of Closed Loop,  
write: CSG, c/o Mary Powers, 73 Ridge Place CR 510, Durango, CO  
81301-8136.

SUBSCRIBING TO CSGnet

When you subscribe to CSGnet, you get this message,  
CSGINTRO.DOC. But you may have received it from a friend who  
printed it, seen it on a demodisk, or seen it on Usenet. To  
subscribe, send a message as follows: (Internet address followed  
by two message commands, one per line)

&nbsp;&nbsp;LISTSERV@VMD.CSO.UIUC.EDU  
&nbsp;&nbsp;Subscribe CSG-L Lastname, Firstname, Affiliation, City, State.  
&nbsp;&nbsp;help

(Lastname, Firstname, etc is optional commentary, but helpful).  
("help" requests a list of most commonly used commands).  
(The Bitnet address is: LISTSERV@UIUCVMD).  
(This server is not sensitive to upper or lower case letters).

CSGnet can also be accessed via Usenet (NetNews) where it is  
listed as the newsgroup bit.listserv.csg-l.

For more information about accessing CSGnet, contact Gary Cziko,  
the network manager, at G-CZIKO@UIUC.EDU

HOW TO OBTAIN TEXT AND PROGRAM FILES

A number of ASCII documents and binary computer programs are  
available on a fileserver maintained by Bill Silvert. It is  
possible to download all these files via e-mail. If you are on  
internet, it is easiest to obtain binary program files via  
anonymous FTP. If you are on MCI mail, you have read about how  
you can transfer binary files with Kermit or Zmodem protocols.  
(Type help at the MCI mail prompt for directions). But the  
server cannot send binary files over the internet mail network,  
so download uue.scr first, then request the binary files  
uuencoded as ASCII files. The Internet address for the server is  
BIOME.BIO.NS.CA. CSGnet files are kept in the subdirectory  
pub/csg.

To get basic information and a current listing of available  
documents, send a message as follows: (Internet)

Commands: help  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ftp  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;get csg/Index  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end

"help" requests commands and explanations.  
"ftp" asks details on anonymous FTP for internet.  
"get csg/Index" requests the Index for the csg subdirectory.

Pay attention to letter case for commands! DOS is not dos.

As part of the index (of the csg directory), you may be looking  
at:

programs/msdos:  
dem1a.exe 128437 Bill Power's demonstr of perceptual control  
dem2a.exe 123649 Bill Power's modelling of control

documents/forssell:  
uud.scr 53406 ASCII Compile uud.exe w DOS debug Dir @ end.

If you want dem1a.exe (uuencoded) to get a "live" demonstration  
of the phenomenon of control, and the ASCII file uud.scr with  
directions at the end on how to use DOS debug to compile uud.exe  
to decode it, send the following message commands:

uue csg/programs/msdos/dem1a.exe  
get csg/programs/forssell/uud.scr

The uuencoded dem1a.exe will be sent in four parts. Remove  
headers and use an editor to make it into one file (starting  
with table and ending with end) before you use uud.exe to  
restore the file. dem1a.exe is a self-extracting archive file.  
Put it in it's own directory before you execute it. You get  
complete documentation and a running program.

LITERATURE REFERENCES

For a complete list of CSG-related publications, get the file  
biblio.pct from the fileserver as described above. Here are some  
selected books and papers on Perceptual Control Theory:

Powers, William T. (1973). \_Behavior: The control of  
perception\_. Hawthorne, NY: Aldine DeGruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The basic text.

\*Robertson, Richard J. and Powers, William T. (Eds.). (1990).  
\_Introduction to modern psychology: The control theory view\_.  
Gravel Switch, KY: CSG Book. ($25 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;College-level text.

\*Powers, William T. (1989). \_Living control systems: Selected  
papers\_. Gravel Switch, KY: CSG Books. ($16.50 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously published papers, 1960-1988.

\*Powers, William T. (1992). \_Living control systems II: Selected  
papers\_. Gravel Switch, KY: CSG Books. ($22 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Previously unpublished papers, 1959-1990.

\*Marken, Richard S. (1992). \_Mind readings: Experimental studies  
of purpose\_. Gravel Switch, KY: CSG Books. ($18 postpaid)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Research papers exploring control.

Marken, Richard S. (Ed.). (1990). Purposeful Behavior: The  
control theory approach. \_American Behavioral Scientist\_,  
\_34\_(1). (Thousand Oaks, CA: Sage Publications)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;11 articles on control theory.

Runkel, Philip J. (1990). \_Casting nets and testing specimens\_.  
New York: Praeger.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;When statistics are appropriate; when models are required.

Hershberger, Wayne. (Ed.). (1989). \_Volitional action: Conation  
and control\_ (Advances in Psychology No. 62). NY: North-Holland.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;25 articles (not all PCT)

Ford, Edward E. (1989). \_Freedom from stress\_. Scottsdale AZ:  
Brandt Publishing.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A self-help book. PCT in a counseling framework.

Gibbons, Hugh. (1990). \_The death of Jeffrey Stapleton:  
Exploring the way lawyers think\_. Concord, NH: Franklin Pierce  
Law Center.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A text for law students using control theory.

McClelland, Kent. (1992). \_Perceptual control and sociological  
theory\_. Not yet published. Available from the author,  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Grinnell University, Grinnell, Iowa.

McPhail, Clark. (1990). \_The myth of the madding crowd\_.  
New York: Aldine de Gruyter.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduces control theory to explain group behavior.

McPhail, Clark., Powers, William T., & Tucker, Charles W.  
(1992). Simulating individual and collective action In temporary  
gatherings. \_Social Science Computer Review\_, \_10\_(1), 1-28.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Computer simulation of control systems in groups.

Petrie, Hugh G. (1981). \_The dilemma of inquiry and learning\_.  
Chicago: University of Chicago Press.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduces PCT to educational theory.

Richardson, George P. (1991). \_Feedback thought in social  
science and systems theory\_. Philadelphia: University of  
Pennsylvania Press.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A review of systems thinking, including PCT.

\*These items are available from CSG Books, 460 Black Lick Road,  
&nbsp;&nbsp;Gravel Switch, KY, 40328.

> **···**
>
> To: SERVER@BIOME.BIO.NS.CA.