Talk:Representativeness heuristic

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Below citation reportedly claims that subjects will avoid answering test questions in a "yes-no-yes-no-yes" pattern (presumably because it doesn't look like a distribution they would expect naturally). I would love if someone with access to an academic abstracts database could confirm this for me.

• Goodfellow, Louis D. (1940). Three-fourths will call heads, etc. Journal of General Psychology, 23, 201-205. cf. Flesch, Rudolf. (1951). The Art of Clear Thinking, p. 132. New York: Harper & Brothers.

--Taak 23:23, 12 Jun 2004 (UTC)

• The example given as the "Taxicab" problem is a poor example. There is a 100% chance that the man says the car is blue (Because that is what color it says he says it is) and there is a 20% chance he got it wrong. Therefore there is an 80% chance that a blue car was involved in the accident using using Bayes' theorem. 100% x 80% = 80. This needs to be clarified, with the misleading phrases and words removed. Instead of saying that he testified that the car was blue, simply say his percentages of getting the color right.

• If your logic is right, then let's extend it: We take the same man and have him look at the sky. He says it is green. Does this mean that there is a 20 per cent chance that the sky is green? Of course not. The reason is that the prior probability of the sky being green is much lower. We all know the sky is blue, and there is a small chance we are all wrong. But it is very small.

Or imagine that we have two people with the same 80/20 error rate look at the sky. One says it is blue, and the other says it is green. By your logic, this means the sky has an 80 per cent chance of being green, and an 80 per cent chance of being blue. These probabilities do no add up to one, which indicates a flaw in your reasoning.

The point of Tversky's experiment was that probability is more complicated than we make it out to be.

• Essentially the question in debate comes down to this: Does the actual color of the taxi affect the probability that the man was correct in his identification? The answer is stated in the experiment itself; he is accurate in his color identification 80% of the time (not 80% of the blue and 80% of the green, but 80% overall). Therefore, the information about the ratio of green to blue taxis is spurious. The 41% figure is erroneous, because that would mean that out of all the possible cases, the correct color would only be identified 59% of the time, by a person with an 80% rate of accuracy. Perhaps this should be clarified within the article.