HF Diagram Test

[From Rick Marken (931022.1500)]

Tom Bourbon (931022.1523) --

Along that line, Martin Taylor described a test he conducted with a
colleague who is a HF person. He asked the person to draw, on a
conventional HF diagram of a person as a control system, the boundary
between environment and person. When the HF person was finished, Martin
drew the boundary as we conceive it in PCT and observed the person's
reactions. The boundary-drawing and -judging exercise seems a good
candidate for inclusion in our study.

Yes, indeed! Excellent idea, Martin. A particularly good "conventional"
diagram is Figure 9.1 (top) on p. 177 of T. Sheridan and W. Ferrel
"Man machine systems" (MIT, 1974).

I would love to hear a description of the HF person's reactions,
Martin. Did they think your boundaries were reasonable? What did
they say? Were they bewildered, satisfied, annoyed, converted?
What a great idea.

Best

Rick

[Martin Taylor 931022 19:30]
(Rick Marken 931022.1500)

On drawing the person-environment boundary on a conventional control
system picture:

I would love to hear a description of the HF person's reactions,
Martin. Did they think your boundaries were reasonable? What did
they say? Were they bewildered, satisfied, annoyed, converted?

There was about half an hour of discussion, which started with bewilderment
(where does the input come from, if it is inside), progressed to some
degree of understanding--perhaps satisfaction--and maybe to future
conversion, at least to a statement that now some of the things he had
been reading about PCT made sense, when they had not done so before.
Annoyance? None.

Actually, an important modification to the picture he drew was to add
the perceptual input function. He had only a line directly from the
CEV to the comparator. He acknowledged the addition (which actually is
normally part of the standard control diagram, as a feedback transform.)

I should point out that the person in question is a control engineer who
is becoming interested in HF problems, rather than the reverse.

Martin