NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/bit/listserv/csgl/2090

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Date:         Fri, 8 Jan 1993 09:34:49 -0800
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[From Rick Marken (930108.0900)]

Martin Taylor (930107 14:00) --

>As to whether the results from one person are useful in dealing with another,
>that depends entirely on what it is that is being measured.  I have 30-year
>old group (as you would say) data on the timing of reversing figures which
>are every bit as tight as any PCT prediction of tracking.

I'll take your word for it; could you send me a reprint? It sounds
very interesting. I didn't mean to imply that all the data from
conventional psychology is useless. If you get group data where
the average results represent almost exactly what each individual
did (no between or within subject variance to speak of) then it
is certainly a worthwhile result.

>In the past, metaphors like gold nuggets among the garbage have been used
>on CSG-L.  The metaphor is reasonable, but the question is whether the
>nugget-to-garbage ratio is low enough to allow a real psychologist (PCT
>oriented) to discard without consideration what fantasy psychologists
>(non-PCT oriented) have done.  I think there is a lot of good stuff that
>can be used.  Bill and Rick and others think not.

I just think that ratio is VERY low; but you do find nuggets,
especially where people are studying control most diretly
(as in operant studies and many perceptual studies). I don't
want to reject stuff without consideration -- but there is a
LOT of stuff out there so its tough to consider everything
carefully to see if it's worthwhile. If you (or anyone) knows
of studies with high quality results then, please, report
them; we certainly will consider them. But the garbage/nugget
analogy is approriate. When you are looking for gold, your
inclination is to spend as much time as possible looking in
the places where you think the gold is most likely to be found.
The same is true with research results -- I prefer to look for
great research where I think it might be found; looking for such
research in conventional psychology seems to me like looking for gold
in the LaBrea Tar Pits -- a good place to look for fossils,
not nuggests (though there might be some gold in the the Tar
Pits, I'd be inclined to search the foothills of the Sierras?).

Greg Williams (920108) ---

>You say I'm a (the?) CSG gadfly. I'm also the CSG archivist, and here
>are some quotes from previous posts on the net to show what you (and
>Rick) actually have said. At one point, you say that correlations of
>".99 upward" are needed for a "true science." And Rick says that
>.99+ is a "reasonable" goal. My point is that you have not reached
> that goal in predicting cursor position.

After reading this I got out my HyperCard conflict stack and
did a tracking run and model run (400 data points each) with a
low conflict and got a correlation between subject and model
mouse movements of .996831 -- the correlation with cursor
movements would be lower but at least we seem to have part of
a true science. I repeated this with a slightly higher level
of conflict and got a sublject/model correlation of .993398. Still
in the "true science" range. Higher conflicts will take us
well below .99 (to .98 maybe?) suggesting that there is something
to be learned there.

>How about H = K * integral(C - T)? (K is a constant to be adjusted for best
>fit to the data by running the simulation with the model in it). That's
>just a first cut, of course, since it doesn't predict the cursor position
>well enough for "true science."

I think the idea, now, is to use your S-R model in a real tracking
situation. As I understand the challenge, you are to derive an S-R
model (like your equation above) from your observation of the
relationship between S (cursor) and R (handle movement). Bill
apparently sent you that data. I'd throw in the disturbance too -- I
don't think it's an unfair advantage for you at all -- in many experiments
you CAN see the disturbance (or the cause thereof) even if the subject can't.
So I would suggest that Bill give you D, C and H from a tracking task.
Based on that data, you come up with an S-R model that generates H based
on what the subject can see (C and T).

Your model must then be tested by seeing if it can do what the subject
does -- control the cursor in a new situation. So your model must be
"run" (this could be cone analytically but it's easier with a computer
simulation) with a new disturbance -- to see if it generates the H that
controls the cursor (as the subject would).

Best

Rick