Why not read what he says?

CSGnet Archive CSG1995
1

[From Bill Powers (950527.2115 MDT)]

Rick Marken (950527.1600) --

     I must not be understanding you correctly when you tell me
     to look at Nachtigall's book for PCT research. I'm sure what
     you must mean is that it might be a good idea to go back and
     look at Nachtigall after we have done the research necessary
     to develop a reasonable PCT model of the controlling done by
     a fly. And I agree with you-- that would be an excellent
     idea. But, of course, unless Nachtigall tested for
     controlled variables, it makes no more sense to look to
     Nachtigall's data for hints about the control system
     organization involved in fly landing than it is to look at
     Atkeson and Hollerbach's data for hints about the control
     system organization involved in limb movement.

I wouldn't have known about the Atkeson and Hollerbach paper if I
hadn't read it. Wouldn't it be simpler just to read Nachtigall?
Maybe he does use a control-system analysis. How can you tell
without reading what he says?

···

-----------------------------------------------------------------
------
Best,

Bill P.

2

<[Bill Leach 950529.02:40 U.S. Eastern Time Zone]

[From Bill Powers (950527.2115 MDT)]

I was almost floored by this posting. Rick specifically asked for a
posting to provide an example of Nachtigall's work that could be PCT
related.

Bruce then posted the interesting but irrelevent (to PCT) example of how
a fly lands on a ceiling.

Rick (presumably wondering at this "PCT" example) blasts it rather
handily and points out that this example provide little encouragement to
read the work.

If I were Rick, I would be more than just a little stunned at your
posting on the matter.

-bill