Sleep study (from Mary)

[from Mary Powers 960829]

Martin (960828)

What Bill was trying to get across is _not_ that special
arrangements were required for the PCT model to work. The issue
in your experiments is what was required for getting good data,
and for what purpose.

Good data in this case meant, first of all, that each subject
should have been able to practice each test until it was well-
learned, in order to derive a good model. As I understand it,
this was not done.

Good data - for Bill - also required limiting _extraneous_
disturbances. The disturbances introduced by picking a mouse up
and resetting it, or using shoulder or body movement rather than
elbow only, really had nothing to do with the experiment, which
was concerned with the effect on tracking tasks of disturbances
contributed by sleep deprivation and drugs. This is why Bill
urged using a joy stick or adapting the mouse. Ditto with
disturbances stemming from variable positions of the head: hence
the suggestion of a chin rest.

I suppose your argument would be that fumbling with the mouse and
head wobble were phenomena that were part of the data - the
physical deterioration of the subjects under the experimental
conditions. But while that was certainly one of the effects of
deprivation, it also had the effect of screwing up the data-
taking during the experimental phase. Bill's aim was to limit the
influence of the gross physical effects, so that what was
happening to the control systems involved in the actual tracking
could be more clearly seen. _And_ use equipment (joystick instead
of mouse) that would not introduce artifacts in the data such as
came about when the mouse was picked up and reset.

The trouble was that the people at DCIEM had the goal of studying
the overall effect of sleep deprivation, and Bill had the goal of
doing basic research on control systems. You apparently got what
you wanted out of the experiment, but as far as Bill was
concerned, the data was garbage, and the whole thing was a waste
of time. A PCT tool was used in this research, rather sloppily.
That Bill had a goal requiring more stringent attention to
experimental design is hardly a justification for questioning the
worth of PCT in general.

          * * *

Ellery - I'm a conservative picture-taker. There are still 8
shots left on that roll. But you will get your photo eventually.

Mary P.