Newsgroups: bit.listserv.csg-l
Date:         Fri, 2 Oct 1992 13:13:23 EST
From:         "j. f. arocha" <CYBN@MUSICA.MCGILL.CA>
Subject:      pct, medicine; questions

[From Francisco Arocha, 921002; 1202)

Question: Is there a reading (a study or a theoretical presentation)
of higher levels of perceptual control? The problem I'm having is that
as I try to understand higher levels in the hierarchy, my
understanding becomes more confused and I have trouble thinking about
an experiment in which I could achieve the degree of precision that is
found in lower levels (the 99%). Do I have to settle for (much) less?
The study that I'm planning (on which some ideas below) I think would
be about category level and above. But I found these less precisely
defined.

A second question: Is there any in the net familiar with the situated
literature, aside from the situated AIers like Chapman & friends? I am
referring to those in that camp who work on "higher" cognition in
psychology and education (Greeno, Seely Brown, William Clancey).

******

PCT and medicine II

As I posted several weeks ago, I'm planing a PCT study in medicine. I
have looked at some verbal protocols with the hope that they help me
understand what the physicians think about. Also I have read some
medical problem solving textbooks and atended a few clases, to see
what is that medical students are taught, and medical ground rounds
(where doctors discuss their cases). This I have done to come up with
some hypotheses. Among the things that I have noted that seem
interesting are the following:

1) there is a lot of disagreement among physicians about most cases.
This disagreement covers the diagnosis itsef as well as the proper
treatment (even if they agree on the diagnosis).

2) the students are taught some rules of thumb that seem to play an
important role in diagnosis. These are things like "common things are
common", "when you hear hoofbeats think of horses not zebras".

3) when doctors or med students give their explanations about a case,
some are more interested in getting the diagnosis right whereas others
are more interested in not missing any fatal disease, to the expense
of being right (actaully, more accurately would be to say that some
physicians mention that what drives their thinking is not to miss an
important disease, whereas others say nothing about this and focus on
producing the correct diagnosis).

4) Some physicians are very sparse in their explanations while others
are very detailed. As far as I can see, there is no connection between
this and getting the right diagnosis.

5) When physicians justify their thinking they focus on different
signs and symptoms. By this I mean that one may mention that what
"triggers" their diagnosis was, say symptom A, whereas another says
symptom B. Again, there does not seem to be any connection between
accuracy in diagnosing (or choosing the "right" treatment) and what
they focus on.

These observations are informal; just by talking with physicians and
med students. I still think that, at least for now, is to do the study
in artificial situation rather than with real cases and real patients.
The reason for this twofold: that I would not know how to do it and
that I think doing it the other way would take me longer than the time
I have (my postdoc ends in june).

I thank David Goldstein and Bill Powers for the comments to my earlier
post. I hope that you both (and any other PCTer) can help me along the
way. I would really like to complete the study.

Saludos,

Francisco
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