Testing conditionals (quiz).

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milky

#279065 Wed, 11 Oct 06 12:09 PM

The card trap

A classic trap was used by Wason and Johnson-Laird (1972).

Four cards are laid out as below:

The conditional statement is now given: 'If a card has one vowel on one side, then it has an even number on the other side.'

The question is to decide which are the minimum cards that need to be turned over to prove that the conditional statement is true.

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Without going in search of the answer, what do you think?

milky

Joined on Thu, Jan 15 2004

Senior Member (3,149)

Hume said that if we had perfect or complete descriptive knowledge of reality, we could not, by reasoning, derive a single valid "ought".

Vowels, Numbers, Conditionals

Clive

#279116 Wed, 11 Oct 06 02:11 PM

Hi,

Two. (E and 4).

Clive

Joined on Thu, Oct 28 2004

Canada

Veteran Member (22,480)

El tango argentino es un pensamiento triste que se puede bailar (The tango argentino is a sad thought which can be danced) Enrique Santos Discépolo

Conditionals

milky

#279282 Wed, 11 Oct 06 09:02 PM

Clive wrote:

Hi,

Two. (E and 4).

Clive

Interesting.

"To affirm the antecedent, E is correct. E is a vowel and thus should have an even number on the other side. If there was an odd number on the other side, the statement would be false, so E must be turned over to check for this.

But choosing 4 is affirming the consequent. Even though 4 is even, it can have a vowel or consonant on the other side and the statement is not falsified."

milky

Vowels, Numbers, Conditionals, Consonants

MrPedantic

#279320 Wed, 11 Oct 06 11:32 PM

Note that Clive's answer ("two") is not incorrect, given the form of the original question. "Minimum" should be omitted.

MrP

MrPedantic

Joined on Wed, Oct 13 2004

Veteran Member (12,167)

...opella forensis / adducit febris...

Conditionals

milky

#279477 Thu, 12 Oct 06 07:53 AM

MrPedantic wrote:

Note that Clive's answer ("two") is not incorrect, given the form of the original question. "Minimum" should be omitted.

MrP

Yes, I wasn't too happy about that "minimum". Anyway, what's your solution to the question?

milky

Conditionals

CalifJim

#279542 Thu, 12 Oct 06 10:18 AM

I don't get it. You just turn over the only one with the vowel (E), don't you?
But where is the rest of the deck? The card with A or I? Don't you need to look on the other side of all the ones with vowels to be sure?
So maybe the answer is 5 - for the 5 vowels.
Or maybe I didn't understand the question.
Tongue Tied [:S]

Anyway, interesting, but where's the linguistics question?
CJ

CalifJim

Joined on Mon, Aug 2 2004

California

Veteran Member (17,705)

"There are no facts, only interpretations" - Nietzsche

Vowels, Conditionals

milky

#279678 Thu, 12 Oct 06 03:31 PM

CalifJim wrote:

Anyway, interesting, but where's the linguistics question?
CJ

Did you miss it?

milky

Conditionals

milky

#279680 Thu, 12 Oct 06 03:33 PM

"Only 4% said E and 7. The 7 could deny the consequent and hence must be checked. If there was a vowel on the other side, the statement would be false.

So what?

Be careful about if-then statements, both in your own use and in those that others use. It does, of course also mean that you can make statements that are logically false and few people will challenge you."

milky