VS: Controling observables (was Re:... long live William T. Powers)

[Eetu Pikkarainen 2017-06-13]

(This is comment to the end of Martin’s message.)

Yes I know that �stabilization� is problematic term and I hope that some English speaker would invent a proper alternative. The general meaning of “stabilization� (to
become stabile) is one (important) special case of the concept for which we need a term. The core meaning of this concept is something like “the process where a subject affects something in the environment in a such way that this something is changed and/or
kept in a such state that the subject gets a perception which is near to his/her reference value�. If this process is looked at from subject’s viewpoint it is “behavior� or “action� but now it should be looked from the viewpoint of the object (that something).
So it is “to be acted on�. I have two suggestions: “constrained� and “adjusted�. (If I remember right Martin once suggested “constrain�?)

Why not “control�? Because in PCT the subjects action is based on (and explained by) the control of perception, where the perceptual signal is compared to reference
signal and if there is difference then that difference is tried to minimize by affecting the object of the perception. So “control� already has a strict and pivotal meaning and use. It is confusing to call one special constituent of that “control� also control.
Of course you could say like Rick that we control by controlling, but then we use the same term for two essentially different processes – essentiallyy different for understanding PCT as a theory. At least they should be clearly marked different for example
by some subscript like:

control(env) and control(per). Control(env) or “environmental control� is the concept used in everyday and (probably) engineering language
where the whole process is projected to the environment. In PCT that control(env) is the part of control(per) (control of perception), the part which takes place in the environment of the controlling subject and is perceivable to observer
and causes consequences for other subjects.

But anyway for me it sounds more clear to use clearly different terms: When we act we
control our perceptions by constraining the environmental objects of our perceptions by our behavior (and by a feedback path).

More technically and generally: “A controlling system (or unit) controls its perceptions by constraining its environment.�

···

Eetu

Lähettäjä: Martin Taylor [mailto:mmt-csg@mmtaylor.net]
Lähetetty: 12. kesäkuutata 2017 21:03
Vastaanottaja: csgnet@lists.illinois.edu
Aihe: Controling observables (was Re:… long live William T. Powers)

[Martin Taylor 2017.05.12.13.14]

[Eetu Pikkarainen 2017-06-12]

EP: The issue is ONLY that we do NOT control anything in the environment but only our own perceptions - even though the control is realized by affecting the environment.

RM: This is simply not true. See my recent post to Martin. I’ll just repeat my last point: If people controlled only their perceptions then there would be no way for anyone other than the person doing the controlling to know this.

The truth of that depends entirely on your definition of control. If the definition of control requires that there be an observer, the underlying philosophy is one that says definitively: “If a tree falls in the forest and no organism is around to hear it,
it DOES NOT make any sound.”, then what you say could possibly be true. Not otherwise. I do not subscribe to that philosophy, and that fact may contribute to a lot of our disagreements. I would say that it doesn’t matter whether anyone else can know whether
you are controlling something – even you may not know it, as according to PCT, most control is unconscious.

As I think of the way the world works, control happens (or does not happen) whether or not there is an external Experimenter/Analyst/Observer available in the neighbourhood to assess the environmental dynamics associated with it. From what Eetu quoted, I understand
you to be saying that “control” is nothing more than a perception in the brain of an observer who has developed a perceptual function, the output of which can be labelled “degree of control”. From your quote above and from your other writing, you think control
does not exist in the world outside the Observer.

EP: I think you partly replied on behalf of in your message [From Rick Marken (2017.06.11.1640)] but only partly. You wrote:

“a controlled perception is an inference based on observation of the fact that certain variables in what is perceived by an observer as the subject’s environment are controlled (maintained in reference states,
protected from disturbance).�

I agree with this quote. Whether the observer perceives control as occurring is different from the Analyst inferring how that control is executed (itself another perception). This is true in both philosophies. What either of them perceives is affected by what
is happening in their real environments, which is where the control they both do (or do not) perceive is (or is not) occurring.

This means that an observer sees something special happen in the environment and from that s/he
infers that the subject is controlling some perception. As part of that inference the observer can do tests and try to disturb the subject’s controlling. What the observer is seeing is not control, but stabilization, see below…

EP: Question is about the definition of control in PCT.

RM: The definition of control in PCT is completely in terms of observable variables.

In engineering it is, but in PCT? Not if one is actually serious about PCT as a theory. In PCT (as in much of science) the observables are only part of the way an Observer sees the world. A PCT observer sees the observables, but sees them only in terms of controlled
perceptions, not as the be-all and end-all of what is happening.

It is an “objective” definition in the sense that others besides the observer can confirm the observation. The definition of control in PCT is: maintenance of a variable in a reference state, protected from disturbance. “Perception” is
not part of this definition; perception is a component of the theory that accounts for this objectively observable phenomenon.

Yes, that’s why a non-PCT observer might use a definition couched in terms of observables only. A PCT observer would take the observables as a starting point confirmable by another observer, not the end point. As several of us have mentioned, not only recently
but over the years, no reference state can be observed in the environment. Reference states must be inferred from the ways the observables change. So “maintenance of a variable in a reference state” implies comparing apples to apples, not apples to oranges
or an observable state to a reference state that is necessarily inferred. However, an inferred state that we call a “Perception” can legitimately be compared with an inferred reference state, and therefore can be controlled. An observable environmental state
cannot.

EP: Perception may not be a part of the definition, but the reference is. Like perception, also the reference is only inside the subject / organism. It is not principally unobservable, but at the current and near future
state of neurology it is not possible to measure the reference value of the subject. So the definition of control (in PCT) cannot be defined completely in terms of observable variables.

Exactly so.

EP: When you see (the fact) that something is (in a certain way and conditions) stabilized in the environment of the subject, you can infer from that to (the fact of) control. It is like all science a hypothetical and
fallible inference, but by experience a more reliable inference than many everyday alternatives. That is just the glory of science: you can know something what you have not (immediately) perceived.

I have to quibble about the word “stabilize” and its relatives, because most of our controlled variables are far from stable. When I type this message, the reference values for my perceptions of the locations
of my fingertips move all over the keyboard, quite quickly. When I walk, reference values for various muscle tensions are always changing. And so it goes, all the way up the hierarchy, the changes getting slower the higher in the hierarchy one goes (all Perceptual
Control Theory, of course).

These rapid (theoretical) variations in reference value make it harder to “observe” control happening. Consider one of Rick’s “mind-reading” demos, in which a number of objects move randomly around the screen (three, but any number could). The subject is asked
to make one of them go where she chooses. If she chooses to make the track look as random as the tracks of the others, there’s no way another person looking at the screen could tell which one was being controlled. But the computer can, because it knows precisely
where the controlled one would go if only it made that decision, moment by moment. Nothing in such a demo would be “stabilized” except the relationship between the subject’s reference location as it changes and her perception of the location as that changes.
And that is not observable by anyone else.

Martin

Eetu,

  Control is the correct term.  Indeed, if you look at the

mathematical underpinnings of control theory, you see that there
is only one situation where error=0 and that is when the control
system does not have to take any action for the controlled
variable status to be equal to the reference value. In other
words, for reasons other than ANY actions on the part of the
control system, the controlled variable is at the desired value.

  This goes clear back to Maxwell's analysis of the

fly-ball-governor. It is currently recognized and has always been
recognized since Maxwell’s time that the infinite gain necessary
to achieve and maintain a condition of zero error is not a
physical possibility.

  The suggestions for an additional term such as stabilize,

constrain, etc. play, I think, directly into the issue that has
resulted in so much net traffic that results when trying to apply
the theory.

  When we talk about a "subject controlling some aspect of the

observed environment" that is reasonable AS LONG as all parties to
the discussion know that in such a discussion based upon PCT the
statement is only a short hand form of a “subject controlling some
perception of an aspect of the observed environment.”

  Adding a term such as suggested would essentially break the PCT

theory connection between what is actually going on and what the
observer/researcher states is going on. Using two different terms
for the same thing would, in my opinion, be claiming that the the
subject is controlling something in the environment WITHOUT the
involvement of perceptions… which is absurd.

  OTOH, a term such as "stabilize" could well be useful in

situations (such a Martin has discussed) where; as a result of
multiple control systems (that is multiple people) controlling
perceptions of various environmental aspects another aspect that
is not necessarily under control by any of the involved parties is
by nature of its relationship to some of the controlled aspects is
"stabilized."Â Indeed, thinking about that last, this could even
be the case for some control action situations of a single
individual.

Best, Bill

···

On 06/13/2017 01:57 AM, Eetu
Pikkarainen wrote:

        [Eetu

Pikkarainen 2017-06-13]

Â

        (This is comment to the end of Martin’s

message.)

Â

        Yes I know that �stabilization� is problematic

term and I hope that some English speaker would invent a
proper alternative. The general meaning of “stabilization�
(to become stabile) is one (important) special case of the
concept for which we need a term. The core meaning of this
concept is something like “the process where a subject
affects something in the environment in a such way that this
something is changed and/or kept in a such state that the
subject gets a perception which is near to his/her reference
value�. If this process is looked at from subject’s
viewpoint it is “behavior� or “action� but now it should be
looked from the viewpoint of the object (that something). So
it is “to be acted on�. I have two suggestions:
“constrained� and “adjusted�. (If I remember right Martin
once suggested “constrain�?)

Â

        Why not “control�? Because in PCT the subjects

action is based on (and explained by) the control of
perception, where the perceptual signal is compared to
reference signal and if there is difference then that
difference is tried to minimize by affecting the object of
the perception. So “control� already has a strict and
pivotal meaning and use. It is confusing to call one special
constituent of that “control� also control. Of course you
could say like Rick that we control by controlling, but then
we use the same term for two essentially different processes
– essentially different for understanding PCT as a theory.
At least they should be clearly marked different for example
by some subscript like:

control(env) and control(per) .
Control(env) or “environmental control� is the
concept used in everyday and (probably) engineering language
where the whole process is projected to the environment. In
PCT that control(env) is the part of control(per)
(control of perception), the part which takes place in the
environment of the controlling subject and is perceivable to
observer and causes consequences for other subjects.

Â

        But anyway for me it sounds more clear to use

clearly different terms: When we act we
control our perceptions by constraining the
environmental objects of our perceptions by our behavior
(and by a feedback path).

        More technically and generally: “A controlling

system (or unit) controls its perceptions by constraining
its environment.�

Â

Â

Eetu

Â

Lähettäjä: Martin Taylor
[]
12. kesäkuutata 2017 21:03
Controling observables (was Re:… long
live William T. Powers)

Â

[Martin Taylor 2017.05.12.13.14]

          [Eetu

Pikkarainen 2017-06-12]

Â

                        EP: The

issue is ONLY that we do NOT control
anything in the environment but only our own
perceptions - even though the control is
realized by affecting the environment.

Â

                RM: This is simply not true. See

my recent post to Martin. I’ll just repeat my last
point: If people controlled only their perceptions
then there would be no way for anyone other than the
person doing the controlling to know this.

      The truth of that depends entirely on your definition of

control. If the definition of control requires that there be
an observer, the underlying philosophy is one that says
definitively: “If a tree falls in the forest and no organism
is around to hear it, it DOES NOT make any sound.”, then what
you say could possibly be true. Not otherwise. I do not
subscribe to that philosophy, and that fact may contribute to
a lot of our disagreements. I would say that it doesn’t matter
whether anyone else can know whether you are controlling
something – even you may not know it, as according to PCT,
most control is unconscious.

      As I think of the way the world works, control happens (or

does not happen) whether or not there is an external
Experimenter/Analyst/Observer available in the neighbourhood
to assess the environmental dynamics associated with it. From
what Eetu quoted, I understand you to be saying that “control”
is nothing more than a perception in the brain of an observer
who has developed a perceptual function, the output of which
can be labelled “degree of control”. From your quote above and
from your other writing, you think control does not exist in
the world outside the Observer.

Â

                  EP: I think

you partly replied on behalf of in your message
[From Rick Marken (2017.06.11.1640)] but only
partly. You wrote:

Â

                  “a controlled

perception is an inference based on
observation of the fact that certain variables in
what is perceived by an observer as the subject’s
environment are controlled (maintained in
reference states, protected from disturbance).�

      I agree with this quote. Whether the observer perceives

control as occurring is different from the Analyst inferring
how that control is executed (itself another perception). This
is true in both philosophies. What either of them perceives is
affected by what is happening in their real environments,
which is where the control they both do (or do not) perceive
is (or is not) occurring.

Â

                  This means

that an observer sees something special happen in
the environment and from that s/he
infers that the subject is controlling some
perception. As part of that inference the observer
can do tests and try to disturb the subject’s
controlling. What the observer is seeing is not
control, but stabilization, see below…

Â

                        EP:

Question is about the definition of control
in PCT.Â

Â

                RM: The definition of control in

PCT is completely in terms of observable variables.

      In engineering it is, but in PCT? Not if one is actually

serious about PCT as a theory. In PCT (as in much of science)
the observables are only part of the way an Observer sees the
world. A PCT observer sees the observables, but sees them only
in terms of controlled perceptions, not as the be-all and
end-all of what is happening.

                It is an "objective" definition

in the sense that others besides the observer can
confirm the observation. The definition of control
in PCT is: maintenance of a variable in a reference
state, protected from disturbance. “Perception” is
not part of this definition; perception is a
component of the theory that accounts for this
objectively observable phenomenon.Â

      Yes, that's why a non-PCT observer might use a definition

couched in terms of observables only. A PCT observer would
take the observables as a starting point confirmable by
another observer, not the end point. As several of us have
mentioned, not only recently but over the years, no reference
state can be observed in the environment. Reference states
must be inferred from the ways the observables change. So
“maintenance of a variable in a reference state” implies
comparing apples to apples, not apples to oranges or an
observable state to a reference state that is necessarily
inferred. However, an inferred state that we call a
“Perception” can legitimately be compared with an inferred
reference state, and therefore can be controlled. An
observable environmental state cannot.

Â

                  EP: Perception

may not be a part of the definition, but the
reference is. Like perception, also the reference
is only inside the subject / organism. It is not
principally unobservable, but at the current and
near future state of neurology it is not possible
to measure the reference value of the subject. So
the definition of control (in PCT) cannot be
defined completely in terms of observable
variables.

      Exactly so.

Â

                  EP: When you

see (the fact) that something is (in a certain way
and conditions) stabilized in the environment of
the subject, you can infer from that to (the fact
of) control. It is like all science a hypothetical
and fallible inference, but by experience a more
reliable inference than many everyday
alternatives. That is just the glory of science:
you can know something what you have not
(immediately) perceived.

Â

      I have to

quibble about the word “stabilize” and its relatives, because
most of our controlled variables are far from stable. When I
type this message, the reference values for my perceptions of
the locations of my fingertips move all over the keyboard,
quite quickly. When I walk, reference values for various
muscle tensions are always changing. And so it goes, all the
way up the hierarchy, the changes getting slower the higher in
the hierarchy one goes (all Perceptual Control Theory ,
of course).

      These rapid (theoretical) variations in reference value make

it harder to “observe” control happening. Consider one of
Rick’s “mind-reading” demos, in which a number of objects move
randomly around the screen (three, but any number could). The
subject is asked to make one of them go where she chooses. If
she chooses to make the track look as random as the tracks of
the others, there’s no way another person looking at the
screen could tell which one was being controlled. But the
computer can, because it knows precisely where the controlled
one would go if only it made that decision, moment by moment.
Nothing in such a demo would be “stabilized” except the
relationship between the subject’s reference location as it
changes and her perception of the location as that changes.
And that is not observable by anyone else.

      Martin

mailto:mmt-csg@mmtaylor.net
Lähetetty:
**Vastaanottaja:**csgnet@lists.illinois.edu
Aihe:

[Eetu
Pikkarainen 2017-06-13]

Â

        (This is comment to the end of Martin’s

message.)

Â

        Yes I know that �stabilization� is problematic

term and I hope that some English speaker would invent a
proper alternative. The general meaning of “stabilization�
(to become stabile) is one (important) special case of the
concept for which we need a term.

ControlDiagramsCompared.jpg

WOW Martin!!

Great points, great presentation!
Best, Bill

ControlDiagramsCompared.jpg

···

On 06/14/2017 08:17 AM, Martin Taylor
wrote:

[Martin Taylor 2017.06.14.08.52]

          [Eetu

Pikkarainen 2017-06-13]

Â

          (This is comment to the end of Martin’s

message.)

Â

          Yes I know that �stabilization� is

problematic term and I hope that some English speaker
would invent a proper alternative. The general meaning of
“stabilization� (to become stabile) is one (important)
special case of the concept for which we need a term.

  I have had to rethink my earlier "quibble" about the use of the

word “stabilize” [Martin Taylor 2017.05.12.13.14]

  ,

because I realize that stabilization is indeed the core of any
kind of control process. The question is the stabilization of
what?

  Here are the two canonical diagrams, one for engineering control

and one for perceptual control. Functionally, they are the same
except for the omission of an analogue to the PCT “Perceptual
Function” in the engineering diagram. Even thought they are
functionally identical, they are usually interpreted differently,
besides which they confusingly use the same labels for different
parts of the loop.

  We don't need to explore the similarities and differences between

these diagrams. All we need to do is ask just what is stabilized.
In the Engineering diagram it is the difference between the
“input” and the “feedback”, whereas in the PCT diagram it is the
difference between the “reference” and the “perception”. In both
cases, that difference is called “error”. If the feedback loop
gain is negative and the gain of the following element (“Plant” or
“Output Function”) is appreciably greater than that of the rest of
the loop, then the circuit will tend to reduce the absolute
magnitude of the error, stabilizing it near zero.

  The perception isn't stabilized. Nor is the engineering "output"

(the PCT “input”). If control works well, engineering “output”
changes as much as the engineering “input” and PCT “input” changes
as much as the PCT “reference”. Indeed, as I pointed out in a
previous message, it may be extremely difficult or even impossible
for an external observer to determine whether a control system is
acting if the reference value is changing as unpredictably as is
the disturbance or more so (PCT language) and the observer can see
only the PCT “input”.

  Of course, if the reference value changes only slowly or is

temporarily fixed, an external observer will see the value of the
externally observable “input” variable to be stabilized, which I
think is why there is confusion over the use of the term
“stabilize” in PCT. Like the reference value, the error value that
is the only truly stabilized variable can never be observed
directly, but must be inferred from observations of the “input”
variable in the “external environment” section of the loop.

  So I think "stabilize" is actually the best word to use in

conjunction with “control”, provided you realize that the essence
of control is the relationship between the reference value and the
perceptual value – the “error”, which is observable in an
engineered system, but not in a biological control system. All
else in the loop, including everything that an external observer
can observe, can vary rapidly and widely, depending on the loop
parameters and on the ways the reference value and the disturbance
value change.

  [Aside: A point that always comes up in this connection is how to

treat the top of the hierarchy, if the reference signal is derived
from the outputs of higher level control units and there are none.
The answer given by Powers is that if the reference value is
fixed, there doesn’t have to be any neural reference signal path,
because that connection is used only to allow the reference value
to vary. Every top-level reference value can be taken to be
permanently zero or any other value determined by the
physiological environment. A reference value, however, must exist
if there is to be control.]

  Martin

[From Rick Marken (2017.06.15.0945)]

ControlDiagramsCompared.jpg

···

Martin Taylor (2017.06.14.08.52)–

MT: I have had to rethink my earlier "quibble" about the use of the word

“stabilize” [Martin Taylor 2017.05.12.13.14] , because I
realize that stabilization is indeed the core of any kind of control
process. The question is the stabilization of what?

MT: Here are the two canonical diagrams, one for engineering control and

one for perceptual control. Functionally, they are the same except
for the omission of an analogue to the PCT “Perceptual Function” in
the engineering diagram.

RM: Also missing from the engineering diagram is a representation of independent disturbances. The Load is not a disturbance because it is in the path of the feedback loop; it’s analogous to the feedback function in PCT (which is not shown in this diagram).Â

MT: Even thought they are functionally

identical, they are usually interpreted differently, besides which
they confusingly use the same labels for different parts of the
loop.

RM:  Right. The variable that is called the Reference in the PCT diagram is called “input” in the engineering diagram. And the variable that is called  “input” in the PCT diagram is called “Feedback” in the engineering diagram. This confusion is one of the reasons why engineering psychologists were unable to apply control theory correctly to the behavior of living systems, the other reason being that engineering psychologists (like all psychologists) thought behavior was a process of output generation rather than control.Â

 
MT: We don't need to explore the similarities and differences between

these diagrams. All we need to do is ask just what is stabilized. In
the Engineering diagram it is the difference between the “input” and
the “feedback”, whereas in the PCT diagram it is the difference
between the “reference” and the “perception”.

RM: Good point. Only the error is kept constant. As you note, the controlled input will vary to the extent that the specification for this input varies.Â

MT: ... it may be extremely difficult or even impossible

for an external observer to determine whether a control system is
acting if the reference value is changing as unpredictably as is the
disturbance or more so (PCT language) and the observer can see only
the PCT “input”.

RM: I don’t believe that that’s true. In my Mind Reading demo, for example, the computer is able to “read the mind” – that is, determine the controlled variable – of a person who is varying the reference for the state of the controlled variable at least as unpredictably as the disturbances to that variable (which are sine waves and, thus, quite predictable).Â

Â

MT: Of course, if the reference value changes only slowly or is

temporarily fixed, an external observer will see the value of the
externally observable “input” variable to be stabilized, which I
think is why there is confusion over the use of the term “stabilize”
in PCT.

RM: I don’t think “stabilize” is a “term” in PCT. It’s not to be found in the index to B:CP, for example. I think it’s just a word that can be used to mean what it means: “keep from changing”. So when you want to talk about keeping some variable from changing you could use the word “stabilize”. But that could apply to a variable that is stabilized by opposing force (like the stability of the walls of my house) or by control (like the stability of the temperature of the water in my swimming pool).Â

Best

Rick


Richard S. MarkenÂ

"Perfection is achieved not when you have nothing more to add, but when you
have nothing left to take away.�
                --Antoine de Saint-Exupery

[Martin Taylor 2017.06.15.14.22]

For once, I am commenting on a message from Rick with which I

largely agree. I like that, when it happens.

[From Rick Marken (2017.06.15.0945)]

True.

The load certainly is not a disturbance, but it is where a

disturbance arrow would enter the loop. For example, if the Load is
a circular saw and the reference/input is its rotational velocity,
disturbances would caused by variations in the material being cut.
The Load is more analogous to the CEV than to any other single part
of the PCT loop, but I think it probably should be distributed over
the PCT diagram, in some cases partly joining the “Plant” as part of
the output function, in other cases standing alone.

I suspect this is correct, and can be used when trying to get

control engineers to understand PCT. The use of the same terminology
for different things and different terminology for the same things
does make the transition unnecessarily difficult. But that’s not
something that can be changed, especially because in the two
different environments “input” in particular enters as a clearly
different place. The Engineer does “input” a reference value,
whereas the organism does “input” data through its senses.

Yes, the computer can do this, but the computer "knows", and more

importantly (if I remember correctly) uses the exact values of the
disturbances at any moment. An outside observer does not. However,
an external observer might be able to guess the controlled avatar if
the subject uses a reference value that has a statistical
distribution different from that of the disturbances. It could be
difficult if the subject is good at mimicing the computer’s
statistics for its disturbance production.

Exactly. It's one word that can be imported from everyday language

without having to be modified for use in PCT. That’s what makes any
word more widely understood and less technical jargon. You know what
“stabilize” means without knowing PCT, and when you come to know PCT
your understanding of it hasn’t changed.

True. Is that a problem? Lots of words mean different things in

different contexts, and there’s no confusion. If you want to relax
in the sun listening to the rippling water of a Highland brook, you
don’t go to the roof of a financial institution to sit on the
“bank”.

Martin

ControlDiagramsCompared.jpg

···

Martin Taylor (2017.06.14.08.52)–

            MT: I have had to rethink my earlier "quibble" about the

use of the word “stabilize” [Martin Taylor
2017.05.12.13.14], because I realize that stabilization
is indeed the core of any kind of control process. The
question is the stabilization of what?

            MT: Here are the two canonical diagrams, one for

engineering control and one for perceptual control.
Functionally, they are the same except for the omission
of an analogue to the PCT “Perceptual Function” in the
engineering diagram.

          RM: Also missing from the engineering diagram is a

representation of independent disturbances.

          The Load is not a disturbance because it is in the path

of the feedback loop; it’s analogous to the feedback
function in PCT (which is not shown in this diagram).

            MT: Even thought they are

functionally identical, they are usually interpreted
differently, besides which they confusingly use the same
labels for different parts of the loop.

          RM:  Right. The variable that is called the Reference

in the PCT diagram is called “input” in the engineering
diagram. And the variable that is called “input” in the
PCT diagram is called “Feedback” in the engineering
diagram. This confusion is one of the reasons why
engineering psychologists were unable to apply control
theory correctly to the behavior of living systems, the
other reason being that engineering psychologists (like
all psychologists) thought behavior was a process of
output generation rather than control.

            MT: We don't need to explore the

similarities and differences between these diagrams. All
we need to do is ask just what is stabilized. In the
Engineering diagram it is the difference between the
“input” and the “feedback”, whereas in the PCT diagram
it is the difference between the “reference” and the
“perception”.

          RM: Good point. Only the error is kept constant. As you

note, the controlled input will vary to the extent that
the specification for this input varies.

            MT: ... it may be extremely

difficult or even impossible for an external observer to
determine whether a control system is acting if the
reference value is changing as unpredictably as is the
disturbance or more so (PCT language) and the observer
can see only the PCT “input”.

          RM: I don't believe that that's true. In my Mind

Reading demo, for example, the computer is able to “read
the mind” – that is, determine the controlled variable –
of a person who is varying the reference for the state of
the controlled variable at least as unpredictably as the
disturbances to that variable (which are sine waves and,
thus, quite predictable).

            MT: Of course, if the reference

value changes only slowly or is temporarily fixed, an
external observer will see the value of the externally
observable “input” variable to be stabilized, which I
think is why there is confusion over the use of the term
“stabilize” in PCT.

          RM: I don't think "stabilize" is a "term" in PCT. It's

not to be found in the index to B:CP, for example. I think
it’s just a word that can be used to mean what it means:
“keep from changing”.

          So when you want to talk about keeping some variable

from changing you could use the word “stabilize”. But that
could apply to a variable that is stabilized by opposing
force (like the stability of the walls of my house) or by
control (like the stability of the temperature of the
water in my swimming pool).

[Dag Forssell 2017.06.15.13.00 PDT]
Martin, Rick,
I would be most interested in your evaluation of Rupert’s discussion of the engineering perspective on control, spelled out in Chapter 3, section 3.4 The Conventional Error, in his Ph.D. dissertation (2000).

To me, this reads as a very complete, easy to understand explanation of what has been and still is wrong with the engineering perspective on control.

Off the top of my head, I can’t think of any other so complete and clear discussion of this.

Rupert’s dissertation can be downloaded here: 1.8 MB.

[https://www.researchgate.net/publication/317381281_Visual_Control_in_Natural_and_Artificial_Systems

](https://www.researchgate.net/publication/317381281_Visual_Control_in_Natural_and_Artificial_Systems)I am thinking about posting it at pctresources.com, with a front page that points to the PCT sections of this dissertation. Rupert said OK.

I think this dissertation will speak to the engineers I want to address with my PCT story.

Best, Dag

···

At 11:53 AM 6/15/2017, you wrote:

[Martin Taylor 2017.06.15.14.22]

For once, I am commenting on a message from Rick with which I largely agree. I like that, when it happens.

[From Rick Marken (2017.06.15.0945)]

Martin Taylor (2017.06.14.08.52)–
MT: I have had to rethink my earlier “quibble” about the use of the word “stabilize” [Martin Taylor 2017.05.12.13.14], because I realize that stabilization is indeed the core of any kind of control process. The question is the stabilization of what?

MT: Here are the two canonical diagrams, one for engineering control and one for perceptual control. Functionally, they are the same except for the omission of an analogue to the PCT “Perceptual Function” in the engineering diagram.

RM: Also missing from the engineering diagram is a representation of independent disturbances.

True.

The Load is not a disturbance because it is in the path of the feedback loop; it’s analogous to the feedback function in PCT (which is not shown in this diagram).

The load certainly is not a disturbance, but it is where a disturbance arrow would enter the loop. For example, if the Load is a circular saw and the reference/input is its rotational velocity, disturbances would caused by variations in the material being cut. The Load is more analogous to the CEV than to any other single part of the PCT loop, but I think it probably should be distributed over the PCT diagram, in some cases partly joining the “Plant” as part of the output function, in other cases standing alone.

MT: Even thought they are functionally identical, they are usually interpreted differently, besides which they confusingly use the same labels for different parts of the loop.

RM:  Right. The variable that is called the Reference in the PCT diagram is called “input” in the engineering diagram. And the variable that is called  “input” in the PCT diagram is called “Feedback” in the engineering diagram. This confusion is one of the reasons why engineering psychologists were unable to apply control theory correctly to the behavior of living systems, the other reason being that engineering psychologists (like all psychologists) thought behavior was a process of output generation rather than control.

I suspect this is correct, and can be used when trying to get control engineers to understand PCT. The use of the same terminology for different things and different terminology for the same things does make the transition unnecessarily difficult. But that’s not something that can be changed, especially because in the two different environments “input” in particular enters as a clearly different place. The Engineer does “input” a reference value, whereas the organism does “input” data through its senses.

[]Â

MT: We don’t need to explore the similarities and differences between these diagrams. All we need to do is ask just what is stabilized. In the Engineering diagram it is the difference between the “input” and the “feedback”, whereas in the PCT diagram it is the difference between the “reference” and the “perception”.

RM: Good point. Only the error is kept constant. As you note, the controlled input will vary to the extent that the specification for this input varies.Â

MT: … it may be extremely difficult or even impossible for an external observer to determine whether a control system is acting if the reference value is changing as unpredictably as is the disturbance or more so (PCT language) and the observer can see only the PCT “input”.

RM: I don’t believe that that’s true. In my Mind Reading demo, for example, the computer is able to “read the mind” – that is, determine the controlled variable – of a person who is varying the reference for the state of the controlled variable at least as unpredictably as the disturbances to that variable (which are sine waves and, thus, quite predictable).

Yes, the computer can do this, but the computer “knows”, and more importantly (if I remember correctly) uses the exact values of the disturbances at any moment. An outside observer does not. However, an external observer might be able to guess the controlled avatar if the subject uses a reference value that has a statistical distribution different from that of the disturbances. It could be difficult if the subject is good at mimicing the computer’s statistics for its disturbance production.

Â
MT: Of course, if the reference value changes only slowly or is temporarily fixed, an external observer will see the value of the externally observable “input” variable to be stabilized, which I think is why there is confusion over the use of the term “stabilize” in PCT.

RM: I don’t think “stabilize” is a “term” in PCT. It’s not to be found in the index to B:CP, for example. I think it’s just a word that can be used to mean what it means: “keep from changing”.

Exactly. It’s one word that can be imported from everyday language without having to be modified for use in PCT. That’s what makes any word more widely understood and less technical jargon. You know what “stabilize” means without knowing PCT, and when you come to know PCT your understanding of it hasn’t changed.

So when you want to talk about keeping some variable from changing you could use the word “stabilize”. But that could apply to a variable that is stabilized by opposing force (like the stability of the walls of my house) or by control (like the stability of the temperature of the water in my swimming pool).

True. Is that a problem? Lots of words mean different things in different contexts, and there’s no confusion. If you want to relax in the sun listening to the rippling water of a Highland brook, you don’t go to the roof of a financial institution to sit on the “bank”.

Martin

I would like to make one comment on this excellent thread section
that is now forming…

  To make things clearer and reduce the need to scroll, I'll delete

all but what I wanted to comment on.

Rick, I suggest that you re-read what Martin actually said.  He did

not say impossible period. The Mind Reading demo does achieve this
but only because the computer program “knows” how the object would
have moved if the subject was not attempting control. I suggest
that in most situations that researchers will be working with it is
indeed either difficult or impossible to know these disturbances and
specifically how the known disturbance would affect the variable in
the environment that is being controlled by the subject. Even there
Martin qualified his statement with “and the observer can see only
the PCT ‘input’.”

···
            MT: ... it may be extremely

difficult or even impossible for an external observer to
determine whether a control system is acting if the
reference value is changing as unpredictably as is the
disturbance or more so (PCT language) and the observer
can see only the PCT “input”.

          RM: I don't believe that that's true. In my Mind

Reading demo, for example, the computer is able to “read
the mind” – that is, determine the controlled variable –
of a person who is varying the reference for the state of
the controlled variable at least as unpredictably as the
disturbances to that variable (which are sine waves and,
thus, quite predictable).

[From Rick Marken (2017.06.16.1050)]

···

Dag Forssell (2017.06.15.13.00 PDT)
Martin, Rick,
DF: I would be most interested in your evaluation of Rupert’s discussion of
the engineering perspective on control, spelled out in Chapter 3, section
3.4 The Conventional Error, in his Ph.D. dissertation
(2000).Â

RM: It’s excellent. And thanks for the pointer to Rupert’s thesis.

BestÂ

Rick

Â

To me, this reads as a very complete, easy to understand explanation of
what has been and still is wrong with the engineering perspective on
control.

Off the top of my head, I can’t think of any other so complete and clear
discussion of this.

Rupert’s dissertation can be downloaded here:Â 1.8 MB.

[
https://www.researchgate.net/publication/317381281_Visual_Control_in_Natural_and_Artificial_Systems

](https://www.researchgate.net/publication/317381281_Visual_Control_in_Natural_and_Artificial_Systems)I am thinking about posting it at pctresources.com, with a front page
that points to the PCT sections of this dissertation. Rupert said
OK.

I think this dissertation will speak to the engineers I want to address
with my PCT story.

Best, Dag

At 11:53 AM 6/15/2017, you wrote:

[From Rick Marken
(2017.06.15.0945)]

Martin Taylor (2017.06.14.08.52)–
MT: I have had to rethink my earlier “quibble” about the
use of the word “stabilize” [Martin Taylor 2017.05.12.13.14],
because I realize that stabilization is indeed the core of any kind of
control process. The question is the stabilization of what?

MT: Here are the two canonical diagrams, one for engineering control
and one for perceptual control. Functionally, they are the same except
for the omission of an analogue to the PCT “Perceptual
Function” in the engineering diagram.

RM: Also missing from the engineering diagram is a representation of
independent disturbances.
The Load is not a disturbance
because it is in the path of the feedback loop; it’s analogous to the
feedback function in PCT (which is not shown in this diagram).
[Martin Taylor
2017.06.15.14.22]

For once, I am commenting on a message from Rick with which I largely
agree. I like that, when it happens.

True.

The load certainly is not a disturbance, but it is where a disturbance
arrow would enter the loop. For example, if the Load is a circular saw
and the reference/input is its rotational velocity, disturbances would
caused by variations in the material being cut. The Load is more
analogous to the CEV than to any other single part of the PCT loop, but I
think it probably should be distributed over the PCT diagram, in some
cases partly joining the “Plant” as part of the output
function, in other cases standing alone.

MT: Even thought they are functionally identical, they are usually
interpreted differently, besides which they confusingly use the same
labels for different parts of the loop.

RM: Â Right. The variable that is called the Reference in the PCT diagram
is called “input” in the engineering diagram. And the variable
that is called  “input” in the PCT diagram is called
“Feedback” in the engineering diagram. This confusion is one of
the reasons why engineering psychologists were unable to apply control
theory correctly to the behavior of living systems, the other reason
being that engineering psychologists (like all psychologists) thought
behavior was a process of output generation rather than control.

I suspect this is correct, and can be used when trying to get control
engineers to understand PCT. The use of the same terminology for
different things and different terminology for the same things does make
the transition unnecessarily difficult. But that’s not something that can
be changed, especially because in the two different environments
“input” in particular enters as a clearly different place. The
Engineer does “input” a reference value, whereas the organism
does “input” data through its senses.

Â

MT: We don’t need to explore the similarities and differences between
these diagrams. All we need to do is ask just what is stabilized. In the
Engineering diagram it is the difference between the “input”
and the “feedback”, whereas in the PCT diagram it is the
difference between the “reference” and the
“perception”.

RM: Good point. Only the error is kept constant. As you note, the
controlled input will vary to the extent that the specification for this
input varies.Â

MT: … it may be extremely difficult or even impossible for an
external observer to determine whether a control system is acting if the
reference value is changing as unpredictably as is the disturbance or
more so (PCT language) and the observer can see only the PCT
“input”.

RM: I don’t believe that that’s true. In my Mind Reading demo, for
example, the computer is able to “read the mind” – that is,
determine the controlled variable – of a person who is varying the
reference for the state of the controlled variable at least as
unpredictably as the disturbances to that variable (which are sine waves
and, thus, quite predictable).

Yes, the computer can do this, but the computer “knows”, and
more importantly (if I remember correctly) uses the exact values of the
disturbances at any moment. An outside observer does not. However, an
external observer might be able to guess the controlled avatar if the
subject uses a reference value that has a statistical distribution
different from that of the disturbances. It could be difficult if the
subject is good at mimicing the computer’s statistics for its disturbance
production.

Â
MT: Of course, if the reference value changes only slowly or is
temporarily fixed, an external observer will see the value of the
externally observable “input” variable to be stabilized, which
I think is why there is confusion over the use of the term
“stabilize” in PCT.

RM: I don’t think “stabilize” is a “term” in PCT.
It’s not to be found in the index to B:CP, for example. I think it’s just
a word that can be used to mean what it means: “keep from
changing”.
So when you want to talk about
keeping some variable from changing you could use the word
“stabilize”. But that could apply to a variable that is
stabilized by opposing force (like the stability of the walls of my
house) or by control (like the stability of the temperature of the water
in my swimming pool).

Exactly. It’s one word that can be imported from everyday language
without having to be modified for use in PCT. That’s what makes any word
more widely understood and less technical jargon. You know what
“stabilize” means without knowing PCT, and when you come to
know PCT your understanding of it hasn’t changed.

True. Is that a problem? Lots of words mean different things in different
contexts, and there’s no confusion. If you want to relax in the sun
listening to the rippling water of a Highland brook, you don’t go to the
roof of a financial institution to sit on the “bank”.

Martin

Richard S. MarkenÂ

"Perfection is achieved not when you have nothing more to add, but when you
have nothing left to take away.�
                --Antoine de Saint-Exupery

[From Rick Marken (2017.06.16.1210)]

···

On Thu, Jun 15, 2017 at 11:20 PM, Bill Leach wrleach@cableone.net wrote:

BL: Rick, I suggest that you re-read what Martin actually said.  He did

not say impossible period.Â

RM: Yes, I know. I guess I just get frustrated by the fact that the only thing that ever gets discussed about the TCV on CSGNet is how it (supposedly) can’t be done in this or that situation. If CSGNet is really supposed to be a place where, as Martin says, “advances and lacunae in Perceptual Control Theory can be discussed in ways that conform to normal science” then, since the TCV is the basic methodology of PCT science, it seems to me that discussions of the TCV should be about how it can be done, not how it can’t.Â

Best

Rick

The Mind Reading demo does achieve this

but only because the computer program “knows” how the object would
have moved if the subject was not attempting control. I suggest
that in most situations that researchers will be working with it is
indeed either difficult or impossible to know these disturbances and
specifically how the known disturbance would affect the variable in
the environment that is being controlled by the subject. Even there
Martin qualified his statement with “and the observer can see only
the PCT ‘input’.”

 RM:Â


Richard S. MarkenÂ

"Perfection is achieved not when you have nothing more to add, but when you
have nothing left to take away.�
                --Antoine de Saint-Exupery

            MT: ... it may be extremely

difficult or even impossible for an external observer to
determine whether a control system is acting if the
reference value is changing as unpredictably as is the
disturbance or more so (PCT language) and the observer
can see only the PCT “input”.

          RM: I don't believe that that's true. In my Mind

Reading demo, for example, the computer is able to “read
the mind” – that is, determine the controlled variable –
of a person who is varying the reference for the state of
the controlled variable at least as unpredictably as the
disturbances to that variable (which are sine waves and,
thus, quite predictable).Â

[Martin Taylor 2017.06.16.15.20]

[From Rick Marken (2017.06.16.1210)]

Aside from the fact that nothing in the prior context was about the

TCV and how it can or can’t be done, and apart from the phrase "* since
the TCV is the basic methodology of PCT science* ", I more or
less agree.

The problem, though, is one that I find frequently in your postings

and publications. It represents a profoundly different approach to
science than mine. Mine is a two-pronged notion that (a) one should
see what seem to be the consequences of what one thinks one knows,
and preferably see if there are viable alternative ways of
developing contrary consequences, and (b) try to demonstrate that
what one knows, or one’s derivation of the consequences, is wrong.
You usually tell us that if one answer fits the facts, then that is
the right answer. I think the objective of science is to figure out
why the obviously correct answer is wrong, and accept it only
provisionally, and then only if there seems no alternative. To find
out that my idea was clearly wrong is a glorious feeling (mixed
perhaps with transient disappointment), because it brings me nearer
to whatever truth science can reveal.

Consider your paper on the relation between target cursor separation

and control quality. You argued that my interpretation was wrong,
and that the controlled variable was the inclination of the line
between target and cursor. I said that my subjective impression was
that you were correct, and you asked me if I would co-author a
paper. I declined, because I could see no way to distinguish the two
possibilities mathematically, since for small angles tan theta is
very close to theta. But you published anyway, declaring victory.

In the case of the TCV, it is important, I think, to define its

strengths and limitations. Under the right conditions, it can be
quite powerful, but when used wrongly, it can mislead. That’s what
powerful tools do. So it’s important to note things like “If the TCV
determines that x+y is better controlled than xy under these
conditions, we can discard x
y as the controlled variable, but we
canNOT say that x+y is the controlled variable; we can say that it
is correlated with the controlled variable.” On the other hand, if
the question is which avatar of three is being controlled, then the
answer is unequivocal.

I think discussions of the TCV should be equally how it can be done

and about how it can’t. The reason I so often point out problems
with it is your gung-ho attitude that it solves all problems and
shouldn’t be questioned. A counterweight is necessary.

Martin
···

On Thu, Jun 15, 2017 at 11:20 PM,
Bill Leach wrleach@cableone.net
wrote:

            BL: Rick, I suggest that you re-read what Martin

actually said. He did not say impossible period.

          RM: Yes, I know. I guess I just get frustrated by the

fact that the only thing that ever gets discussed about
the TCV on CSGNet is how it (supposedly) can’t be done in
this or that situation. If CSGNet is really supposed to be
a place where, as Martin
says, “advances and lacunae in Perceptual Control Theory
can be discussed in ways that conform to normal science”
then, since the TCV is the basic methodology of PCT
science, it seems to me that discussions of the TCV
should be about how it can be done, not how it can’t.

                          MT: ... it may be

extremely difficult or even impossible for
an external observer to determine whether
a control system is acting if the
reference value is changing as
unpredictably as is the disturbance or
more so (PCT language) and the observer
can see only the PCT “input”.

                        RM: I don't believe that that's true. In

my Mind Reading demo, for example, the
computer is able to “read the mind” – that
is, determine the controlled variable – of
a person who is varying the reference for
the state of the controlled variable at
least as unpredictably as the disturbances
to that variable (which are sine waves and,
thus, quite predictable).

[From Rick Marken (2016.06.16.1725)]

···

Martin Taylor (2017.06.16.15.20)–

MT: ... You usually tell us that if one answer fits the facts, then that is

the right answer.

RM: I don’t remember ever telling anyone that.Â

Â

MT: I think the objective of science is to figure out

why the obviously correct answer is wrong, and accept it only
provisionally, and then only if there seems no alternative. To find
out that my idea was clearly wrong is a glorious feeling (mixed
perhaps with transient disappointment), because it brings me nearer
to whatever truth science can reveal.

RM: Well, that’s a bit closer to what I think. Though I would probably just say that I think the objective of science is to test theories against data, change the theory based on the data, if necessary, and test again.Â

MT: Consider your paper on the relation between target cursor separation

and control quality. You argued that my interpretation was wrong,
and that the controlled variable was the inclination of the line
between target and cursor.

RM: Right, I tested your theory against observation and found that it did more poorly than another theory, one based on PCT.Â

Â

MT: I said that my subjective impression was

that you were correct, and you asked me if I would co-author a
paper. I declined, because I could see no way to distinguish the two
possibilities mathematically, since for small angles tan theta is
very close to theta. But you published anyway, declaring victory.

RM: I published because I knew how to distinguish the two models in terms of their fit to observation (the data). The paper is reprinted as Chapter 4 in “Doing Research on Purpose”, though the graphs are probably easier to read in the original article. It’s title is “Testing for Controlled Variables” and I thought it provided a great illustration of how to do the TCV using modeling. Sorry you didn’t like it but thanks for the data.

MT: In the case of the TCV, it is important, I think, to define its

strengths and limitations. Under the right conditions, it can be
quite powerful, but when used wrongly, it can mislead.

RM: Of course, any tool used wrongly (my god, that is a word; sounds like something Trump would say;-) can mislead. That’s not a limitation of the TCV; that’s a limitation of the user of the TCV.

MT: So it's important to note things like "If the TCV

determines that x+y is better controlled than xy under these
conditions, we can discard x
y as the controlled variable, but we
canNOT say that x+y is the controlled variable; we can say that it
is correlated with the controlled variable." On the other hand, if
the question is which avatar of three is being controlled, then the
answer is unequivocal.

RM: Â This is the kind of thing I would like to see in discussions of the TCV. This is not a limitation of the test; it’s something that a researcher should know about when doing the test; the TCV provides only closer and closer approximations to the actual controlled variable. By the way, even the position of the avatar is not unequivocally the actual controlled variable, though it is very close; close enough for mind reading.Â

Â

MT: I think discussions of the TCV should be equally how it can be done

and about how it can’t. The reason I so often point out problems
with it is your gung-ho attitude that it solves all problems and
shouldn’t be questioned. A counterweight is necessary.

RM: And I will continue to be a counterweight to your counterweight. The TCV is THE methodology for studying living control systems. The PCT model explains behavior in terms of the TYPES of perceptions that organisms control. It is the only methodology discussed by Powers in B:CP and other publications. I don’t know what your counterweight to the TCV is but I haven’t seen any research testing PCT using anything other than the TCV. Indeed, if you’re not using some version of the TCV then you can’t possibly be testing PCT. Maybe you’re testing some other control model of behavior – and there are others - but only PCT is a model of behavior as the control of different TYPES of perception. Testing PCT has to involve testing to see what those types of perceptions are.

BestÂ

Rick

Richard S. MarkenÂ

"Perfection is achieved not when you have nothing more to add, but when you
have nothing left to take away.�
                --Antoine de Saint-Exupery

[From Rupert Young (2017.06.17 13.00)]

  I've just been updating versions of these based on Wiener's

original, with additional PCT labels. Do these look correct in
terms of labels and separation between organism and the world?

ledklgdblnfmohng.png

ecojkmojkojmlpgg.png

Regards,
Rupert

···
            DF: I would be most interested in your evaluation of

Rupert’s discussion of
the engineering perspective on control, spelled out in
Chapter 3, section
3.4 The Conventional Error , in his Ph.D.
dissertation
(2000).

[From Fred Nickols (2017.06.17.1435 ET)]

Well, my test message got through so I’ll try this one again.

I think if it were up to me I’d place “Sensory Input� in the second diagram inside the organism and over by the comparator.

Fred Nickols

16f0a861.png

16f0a951.png

···

From: Rupert Young [mailto:rupert@perceptualrobots.com]
Sent: Saturday, June 17, 2017 7:51 AM
To: csgnet@lists.illinois.edu
Subject: Re: VS: Controling observables (was Re:… long live William T. Powers)

[From Rupert Young (2017.06.17 13.00)]

DF: I would be most interested in your evaluation of Rupert’s discussion of the engineering perspective on control, spelled out in Chapter 3, section 3.4 The Conventional Error, in his Ph.D. dissertation (2000).

I’ve just been updating versions of these based on Wiener’s original, with additional PCT labels. Do these look correct in terms of labels and separation between organism and the world?

Regards,
Rupert

[John Kirkland (2017.06.18 0800 Med time)]

Quick question to Martin:

When pondering over your suggested trinity a question popped into my mind: what could be the reference status of B:CP ? (enjoy the pun).

Cheers

16f0a951.png

16f0a861.png

···

On Sun, Jun 18, 2017 at 9:21 AM, Dag Forssell csgarchive@pctresources.com wrote:

[From Dag Forssell (2017.06.17.1420 PDT)]

Fred has a good point here. I missed that end in my pdf reply.

Perhaps if you move the vertical next to Sensory input out, move Sensory
input to the left side of it, and include all of the effector (all
muscle?) the diagram could feature a clean dotted line alignment.

Best, Dag

[Fred Nickols (2017.06.17.1435
ET)]
Â
Well, my test message got through so I’ll try this os one again.
Â
I think if it were up to me I’d place â₢€œSensory Input†in the second
diagram inside the organism and over by the comparator.
Â
Fred Nickols
Â
From: Rupert Young
[
mailto:rupert@perceptualrobots.com]
Sent: Saturday, June 17, 2017 7:51 AM
To: csgnet@lists.illinois.edu
Subject: Re: VS: Controling observables (was Re:… long live
William T. Powers)

Â

[From Rupert Young (2017.06.17 13.00)]
DF: I would be most interested in your evaluation of Rupert’s
discussion of the engineering perspective on control, spelled out in
Chapter 3, section 3.4 The Conventional Error, in his Ph.D.
dissertation (2000).Â

I’ve just been updating versions of these based on Wiener’s
original, with additional PCT labels. Do these look correct in terms of
labels and separation between organism and the world?

Â

Â

Regards,

Rupert

Â

Â

I think if
it were up to me I’d place “Sensory Input� in the second
diagram inside the organism and over by the comparator.

[Martin Taylor 2017.06.18.11.53]

[John Kirkland (2017.06.18 0800 Med time)]

Quick question to Martin:

When pondering over your suggested trinity a question popped into my mind: what could be the reference status of B:CP ? (enjoy the pun).

Olympus?

Martin