Self-study
In Debbie's magic act, a volunteer supposedly selects a card in a random fashion, looks at it without showing it to her, and replaces it in the deck. █████ ███████ █████████ ██████ ████ ███ ████ ███ ██████████ ███████ ███ ████ ████████ █████ █ ███████ █████████ █████ ███████ ██ ███ ██████ ██████ ███ ███████████ ███ ██ ███████ ██ ████ ███ ██████ ██ ███ ███████ ███ ███████ ███████ ████████ █ ████████ ████ ██ ██████ ███ ███ █████ ██████ ███ ███████ ████████ ███ █████ ████ █████ ██████ ██████████ ████████ ███ ████████ █████ ███ ███████ █████████ ████ ██████ ████ ███████ ███████ ██ █████ ███ █ █████ █████ ███ █ ███████ ███████████ ██ ███████ ███ ███████
Summarize Argument
The skeptic concludes that Debbie doesn’t use sleight of hand, a trick deck, or a planted “volunteer” in her magic act. He supports this by conducting three trials to eliminate these tricks. In each trial, Debbie successfully revealed the selected card.
(1) He videotaped Debbie doing the trick and did not find a sleight of hand.
(2) He provided her with a standard deck of cards for the trick.
(3) He selected the card himself.
Identify and Describe Flaw
By testing and eliminating each trick in isolation, the skeptic assumes that Debbie only ever uses one of them. In other words, he assumes that she never switches between them to perform her act.
7.
Which one of the following ████ ██████████ █████████ █ ████ ██ ███ █████████ ██████████
a
The skeptic failed ██ ████████ ███ ███████████ ████ ██████ ███ ███ ██████ ███ ███ ████ ██████ ██ ███████ ███ ███████
This highlights a key flaw in the skeptic’s reasoning. By testing for one trick at a time, he missed the possibility that Debbie could’ve been switching between them to achieve her effect. For example, she could’ve used sleight of hand when he tested for a trick deck, and so on.
b
The skeptic failed ██ ████████ ███ ███████████ ████ ███████ ██ ████ █████ ████ ██ ████████ ██ ████ █████ █████ ████ ████████████
As long as videotaping can detect sleight of hand, it doesn’t matter if there are also other ways to detect it.
c
The skeptic failed ██ ████████ ███ ███████████ ████ ██████ ████████ ████ ███████ ██ ████ ███ █ █████ ████ ██ ███████ ███ ███████
The skeptic doesn’t over look this; in fact, he tests for both of these tricks. If Debbie requires both sleight of hand and a trick deck, she would’ve failed both of the first two trials.
d
The skeptic failed ██ ████████ ███ ███████████ ████ ██████ ████ █████████ █████ ████ ███████ ██ █████ █ █████ █████ ██ █ ███████ ███████████ ██ ███████ ███ ███████
The skeptic doesn’t conclude that Debbie doesn’t use any trick to achieve her affect, only that she doesn't use sleight of hand, a trick deck, or a planted “volunteer.” Even if she does use some other trick, it wouldn’t affect his conclusion.
e
The skeptic failed ██ ████████ ███ ███████████ ████ ████████ ███████ ██ ███ █████ ██████ ███ █████████ █████ ████ █ ████████████
This is irrelevant because the skeptic never claims that her success was due to coincidence. He just claims that it wasn’t due to any of the three tricks that he tested her for.