Selecting

CSGnet Archive CSG1996
1

From Stefan Balke (960305.1100 MEZ)

Rick Marken (960301.1400)

The current model of this selection process is random reorganization;

I agree, however, that subjectively it seems like I select references non-
randomly when I am reorganizing;

This fits with my subjective experience. I don´t feel myself guided by a
random process.

when I was dating (and thus, constantly
reorganizing), for example, I tended to take my date to a nice retaurant, a
play or a concert rather than a porno movie (as DeNiro did in "Taxi Driver")
in order to achieve my not altogether wholesome goals. I don't know whether
any of these behaviors actually helped me control any better, but I did have
a bias away from the "Taxi Driver" option.

Isn´t this bias a contradiction to the assumption of a random process?
Why is it better to assume a random process instead of a expectancy X value
assumption?

Regards, Stefan

P.S.: I can´t remember, what did DeNiro want to reach with his date and was
he successful? :wink:

2

[From Rick Marken (960305.0800)]

Stefan Balke (960305.1100 MEZ) --

Isn't this bias [in the reorganization process] a contradiction to the
assumption of a random process?

Yes. If such a bias really exists, and if it's part of the reorganization
process, then we would have to change the reorganization model from random to
biased.

Why is it better to assume a random process instead of a expectancy X value
assumption?

It's not really a matter of "better". There is just very little data on this
matter, other than subjective experience. Until there is some data that
suggests a non-random reorganization process, it seems to me like the most
reasonable assumption is that reorganization is random.

Random reorganization makes sense because (as Hugh Petrie pointed out in a
discussion of the "Meno Paradox") when you are learning to control (without a
teacher helping you) you really have no idea what to do to achieve control.
For example, suppose you are learning to screw in a light bulb (I assume you
already know how to screw in a bed;-)). Let's assume that you already know
that the bulb goes in a socket and that it must be rotated to be screwed in.
The only thing you don't know is the direction in which to rotate the bulb --
clockwise or counterclockwise. So you have to learn how to rotate the bulb in
order to be able to control for it being screwed in.

To learn how to control for screwing in a light bulb, then, you have to try
rotating the bulb. So which direction of rotation do you try first? The PCT
reorganization model says that you basically flip a mental coin; heads you
try clockwise, tails you try counterclockwise.

The notion of random reorganization just says that when there is no basis for
determining what relationship between error and action will work (to give
control); so you select actions (to reduce the error) randomly. But, again,
this is just a _guess_ about how reorganizxation might work. What we need
in ordwer to test this idea is _data_ that shows how people learn the
relationship between error and action when they are learning to control.

P.S.: I can't remember, what did DeNiro want to reach with his date and was
he successful? :wink:

A restored print of "Taxi Driver" has been released here in the US. But I
recommend the videotape if you can get it. Very interesting flick. And, no,
the DeNiro character's dating strategy did not work.

Best

Rick

3

[Hans Blom, 960306a]

(Rick Marken (960305.0800))

For example, suppose you are learning to screw in a light bulb (I
assume you already know how to screw in a bed;-)). Let's assume that
you already know that the bulb goes in a socket and that it must be
rotated to be screwed in.

A psychologist can really be knowledgeable about such matters? ;-).

The only thing you don't know is the direction in which to rotate
the bulb -- clockwise or counterclockwise. So you have to learn how
to rotate the bulb in order to be able to control for it being
screwed in.

Are you certain that it takes just ONE psychologist to screw in a
light bulb? ;-).

To learn how to control for screwing in a light bulb, then, you have
to try rotating the bulb. So which direction of rotation do you try
first? The PCT reorganization model says that you basically flip a
mental coin; heads you try clockwise, tails you try counterclock-
wise.

If you have already screwed in a lot of things in your lifetime --
screws, spark plugs, cork screws, what have you -- you may remember
that most of those required a clockwise movement. Why? Because it is
better that way? Because an electric current and the magnetic field
caused by it behave thus? No, it just seems that our culture has a
predilection for doing the screwing that way. Remembering this "law"
may save some effort; mentally, because you don't have to flip mental
coins, and physically, because attempts will succeed immediately.

Always? No, not always. I've encountered some objects -- bolts on
some of the wheels (can't remember now whether those were the right
side or the left side wheels, but there ought to be a logical expla-
nation) of some French automobiles -- that had to be screwed in in an
anticlockwise manner. Yet, on average, trying clockwise first will
save effort.

Do you see the relation with model-based control?

Greetings,

Hans

···

================================================================
Eindhoven University of Technology Eindhoven, the Netherlands
Dept. of Electrical Engineering Medical Engineering Group
email: j.a.blom@ele.tue.nl

Great man achieves harmony by maintaining differences; small man
achieves harmony by maintaining the commonality. Confucius