[Martin Taylor 2018.07.16.15.12]
[Bruce Nevin 2018-07-16_15:08:09
ET]
I would prefer to see a working
simulation of either model, in which control systems
implemented on a computer deviate from ‘perfect control’ (i.e.
uniform speed around an ellipse) in the same way as living
control systems, as an unintended side effect of control.
As well you have known for a very long time, I have insufficient
hubris to attempt a model of observed behaviour before trying the
TCV to figure out what variable(s) might be being controlled during
the task. I have no means to do the TCV needed, so I refrain from
suggesting a model. You are not so inhibited.
However, as you also know, my critiques have never had anything to
do with your model, except early on when you presented a model that
faithfully tracked a target whose movements exhibited the power-law
relationship and claimed that this model solved the problem. Then in
your rebuttal to our comments on your original paper, you did the
same thing, and called the helicopter tracking model a PCT model of
the power law, which it is not. It is a model of tracking, when the
thing tracked follows a power law.
For the record, here are just eight of the falsehoods you
incorporated in your rebuttal of my comment on the Marken and
Shaffer paper (copied from [Martin Taylor 2018.03.08.23.07]).
Despite having been made aware of their falsity, yet you continue to
repeat some of them on CSGnet. Why do you do that?
----------begin quote (replacing references to "you" with references
to “they”, and added numbering)-------
* (1) In the very first paragraph you claim that my reason for
writing a critique was that the idea that the power law might be a
behavioural illusion caused “consternation”, whereas I made
explicit that nothing in my critique had any bearing on that
issue. Indeed, I finished my critique with the statement that
perhaps the power law is indeed a behavioural illusion, though
M&S sheds no light on that issue.* * (2) M&S say that my critique of their use of Gribble and
Ostry’s equations is based on my belief that those equations are
wrong or misleading, whereas I pointed out that they are well
known and universally accepted equations for using observed data
to measure the velocity (equation 1) and curvature (equation 2)
profiles observed in an experiment. Neither Gribble and Ostry nor
(so far as I know) anyone other than Marken and Shaffer ever
claimed that the observed velocity was the only velocity that
could be used to get the correct curvature from the equation for
R.* (3) I never said that the derivation of V = R*1/3D1/3** was wrong. I said that since the formula for D was velocity (V)
times a constant in spatial variables, the equation is not an
equation from which one can determine V. The M&S claim that it
is an equation from which one can determine V is the core of my
critique.* * (4) M&S falsely claim that I argue that “it should have
been obvious that X-dot and Y-dot are derivatives with respect to
time in the expression for V, whereas they are derivatives with
respect to space in the expression for R (p. 5)”. On the contrary,
I devote the first couple of pages of my critique to showing why,
despite the radius of curvature being a spatial property,
nevertheless it is quite proper to use time derivatives in the
formula for R.* * (5) M&S say that because Gribble and Ostry correctly
transformed Viviani and Stucchi’s expression for R using spatial
derivatives into one using time derivatives (a derivation with
which I started my comment), therefore they were correct to say
that ONLY the velocity found in an experiment can be substituted
into the numerator of the expression for R, whereas both my
derivation and that of Viviani and Stucchi (essentially the same)
makes it crystal clear that this is not true.* * (6) M&S follow this astounding assertion with an couple
of paragraphs to show why the V = R**1/3D1/3** equation is correct, implying that my comment claimed it to be
wrong. Early in my comment, however, I wrote: “They then write
their key Eq (6) [V = R**1/3D1/3** ],
which is true for any value of V whatever…” Any implication that
my comment claimed the equation to be incorrect is false.* * (7) Omitted Variable Bias: My comment demonstrated that the
finding predicted and reported by M&S was actually a tautology
having no relation to experimental findings, which will always
produce the result claimed by M&S to be an experimental
result. M&S in the paper and in the rebuttal treat it as a
discovery that can be made only by careful statistical analysis,
and do not acknowledge the tautology criticism at all.* * (8) M&S: “At the heart of the criticisms of our paper by
Z/M and Taylor is the assumption that the power law is a result of
a direct causal connection between curvature and speed of movement
or between these variables and the physiological mechanisms that
produce them.” I have no idea how this astonishing statement can
be derived from my exposition of the mathematical and logical
flaws in their paper. My comment is designed to refute exactly
M&S’s claim of my motivation. The comment shows that there is
NO necessary relationship, causal connection or otherwise, between
curvature and speed of movement.
- --------end quote-------
I repeat from my last message: *"* What's the advantage to you
of refusing to deal with scientific points people bring up about
your work?"
Well, I guess predictions aren't always wrong, and I am indeed not
surprised.
Martin
···
[Rick Marken 2018-07-16_08:16:06]
[Martin Taylor 2018.07.14.23.06]
MT: That's really good! Your reference state for a
variable is correct because it agrees with your
reference state for that variable.
RM: No, my reference state for PCT is correct
because reference states define the “correct” way for
our experiences to be. My reference state for PCT
defines the correct experience of PCT for me; yours
defines the correct experience of PCT for you. Yours
is wrong relative to my reference, though not that
wrong; I thought your reply to Rupert regarding
Gestalt robotics was quite good. But your view of PCT
is wrong relative to my reference for PCT in some
significant dimensions. Ergo, the conflict.
MT: Since in your rebuttal you refused to engage ANY
of the criticisms in my comment note, but
substituted instead never-made criticisms you were
able to refute, I think that statement goes into the
gallery of the great untruths of the age. Why make
it?
RM: Well, I think if you read my rebuttal carefully
you will see that it demonstrates the basic problem
with research on the power law of movement: the
problem is that it is based on a misconception of the
nature of behavior itself. It is based on the idea
that behavior is caused output rather than controlled
input.
RM: But I think that one way to make this argument
more productive would be for you to present your model
of curved movement – a model that produces curved
movements in a way that that explains the observation
of a power law relationship between the instantaneous
curvature and velocity of these movements. I’ve shown
you mine – what I think is the PCT model – now I see
you and call you; what’s your model?
MT: "Correct" presumably
means a correspondence with
something else.
RM: Yes, with my reference for the
state of that variable.
RM: So what I believe
is that there exists a
“correct” reference
state for that variable
– the state that Bill
was controlling for as
evidenced in his
writings, conversations
and demonstrations.
RM: And my published rebuttal to your
published rebuttal showed that what your
analysis and conclusions from it were
completely wrong.
Best
Rick
What's the
advantage to you of refusing to deal with scientific
points people bring up about your work? In what
perception you control would it create error if you
were to accept normal mathematics or physics as
being valid? When your work is good, it’s good, but
when you make a mistake, why does it seem so
difficult for you to correct it? In the curvature
paper none of the criticisms were relevant to a PCT
interpretation, but you make out that all of them
were intended to refute a “correct PCT analysis” of
the experimental findings. Why?I don't expect an answer to a question raised, but I
wouldn’t be surprised at an answer to something
completely different.