# LCS III: Chapter 2

[David Goldstein (2014.03.09.11:04)]

Listmates, I am posting my answers to the study guide I posted. I don’t see any more people posting answers.

Study Guide for Chapter 2 of LCS
III

What
levels of perception are needed to perform the task of chapter 2? Recall that a display changes in three
waysleft/right position, shape (round/nonnround), and axis orientation
(pointing towards you/not towards you). Donât forget the levels of perception

My
answer: left/right sounds like a relationship; round/nonround is a
configuration; pointing towards you/not towards you sounds like a relationship.

On
Page 22, Bill says: âThe only thing that changed was which aspect you decided
to pay attention to and hold constant.â? Where does this happen in the PCT
model?

My
answer: Awareness is associated with the reorganization system in PCT.

Based
on your answer to question 1, which aspect of the display do you think a person
should be able to control better and why?

My
answer: The lower the level, the less time involved in constructing the
perception. Based on this, since configuration is lower than relationship, I
would expect that shape would be easier and faster to control.

Consider
Billâs statement on page 25: âA second way to find the controlled variable is
to look for the minimum correlation between the disturbance and the aspect of
the ball being influenced by the disturbance.â?
Can you explain this in terms of the properties of the correlation
statistic? (hint: what happens to the size of a correlation coefficient when
the range of one of the variables is restricted?)

My
answer: Rick disagreed with my hint. However, the size of a correlation
coefficient does decrease with a restriction of range. Rick points out that the
restriction of range is due to control.

From
pages 27 to 35, Bill introduces the basic concept of a negative feedback
control system. On Page 28, he says: âIt has to sense the variable under
control to know whether its magnitude is less than or greater than the desired
magnitude and of course the controller must affect the controlled aspect so it
can be brought closer to the desired value (which requires a comparison). What order do you think is best for acquiring
a new control system using the three components of input, comparator and out
functions?

My
answer: Bill has written an article about PCT applied to development. He
proposes the learning order to be: input component, comparator component,
output component. I can provide the reference for interested people.

The
addendum to chapter 2, from pages 35 through 40, has been involved in our
current discussion of Ashby and feedback versus feed forward. I would simply
like to direct you to a research project that Bill and I did with adults which
made use of the transfer function approach rather than the modeling approach. Go to:

http://www.pctweb.org/Tracking.pdf