Here's one from the TIPS archives (September, 1996) that I had forgotten
all about.
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Archive-Date: Wed, 25 Sep 1996 13:29:02 EDT
Date: Wed, 25 Sep 1996 11:52:38 EDT
From: "Britt, Michael" <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
To: teaching in psychology <[EMAIL PROTECTED]>
Subject: psychic ability demo - works well
I tried this "psychic ability" demo the other day in class (given
to the tips list a long time ago by Gary Peterson) and it worked
great. It really starts a good discussion on Falsifiable hypotheses,
how we allow others to trick us, how we need to set up a fair test
of our hypothesis, etc. It is also enjoyable...
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Here's another trick I got from Dave Myers who got it from his
son who got it from Penn and Teller....
Write (and announce you are making a prediction) on a slip of
paper (or on the blackboard behind a movie screen), your premonition.
Write, (don't yet disclose this) "You will choose the 3 pile."
Then lay out three piles of cards and simply ask a volunteer to
choose one, and confirm with them that it is the pile they really want.
If they pick one to your left, the student's right, confirm that the
student wishes not the first or the second pile, but this third
pile...then reveal your correct prediction.
The middle pile should contain the four "3" cards, which can be revealed
if chosen (after you show the right and left piles which have a random
mix of cards). Your prediction will be correct again!
The pile to your left should have five cards. The middle pile the four
threes, and the right pile any 3 cards. Thus, if the latter pile is
chosen, you count the three piles, demonstrating that the person has
chosen not the five card or the four-card pile, but the three pile.
Have the cards arranged already in the deck so that you can just deal
out
the three pilews and have them end up properly in the piles. Try it!
I have found this to be good to get the students to explore possible
hypotheses and alternative explanations to the psychic one. Unless, you
have the audience against you, they will enjoy this, but a few will come
close to guessing that you have many possible outs. Typically though,
they think you are sending nonverbal cues to have the right pile
selected...a good alternative explanation that can lead to discussion of
experimenter bias and the clever hans story.
Gary [EMAIL PROTECTED]
Try to check out: Bates, J. A. (1991). Teaching hypothesis
testing by debunking a demonstration of telepathy. _Teaching of
Psychology,_ 18(2), 94-97.
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Thanks again, Gary, for the idea!
Mike
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Michael A. Britt, Ph.D. e-mail: [EMAIL PROTECTED]
Psychology Department fax : (914) 575-3640
Dyson 339 tele : (914) 575-3000 x2972
Marist College
Poughkeepsie, N.Y. 12601
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Sue Frantz [EMAIL PROTECTED]
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New Mexico State Univ. - Alamogordo Fax: (505)439-3802
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