Reasoning and Problem Solving
Tversky and Kahneman examples
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A Discussion on Kahneman and Tversky's perspective by Thayer Watkins, San Jose State
More theoretical summaries--MITECS  -- Thomas Gilovich

Example 1:   Bill is 34 years old. He is intelligent, but unimaginative, compulsive, and generally lifeless. In school he was strong in mathematics but weak in social studies and humanities.

Please rank order the following statements by their probability, using 1 for the most probable and 8 for the least probable

a) Bill is a physician who plays poker for a hobby.
b) Bill is an architect
c) Bill is an accountant
d) Bill plays jazz for a hobby
e) Bill surfs for a hobby
f) Bill is a reporter
g) Bill is an accountant who plays jazz for a hobby
h) Bill climbs mountains for a hobby
 
Example 2:   Linda is 31 years old, single outspoken and very bright. She majored in philosophy. As a student she was deeply concerned with the issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.

Please rank order the following statements by their probability, using 1 for the most probable and 8 for the least probable

a) Linda is a teacher in elementary school
b) Linda works in a bookstore and takes Yoga classes
c) Linda is active in the feminist movement
d) Linda is a psychiatric social worker
e) Linda is a member of the League of Women voters
f) Linda is a bank teller
g) Linda is an insurance salesperson
h) Linda is a bank teller and is active in the feminist movement
 
Example 3:   Imagine urns filled with balls, of which 2/3 are one color and 1/3 another. that is there are twice as many of one color as the other.
Assume that you drew 5 balls, 4 red ones and 1 white one from Urn A.
Also assume that you drew 20 balls, 12 red and 8 white from Urn B.

Suppose that one of the Urns has more white balls than red ones. Which of the two is more likely to have more white balls, A or B?
 

Example 4:  The frequency of occurrence of letters in the English language was studied. In typical texts, the relative frequency of letters in the first and third position was tallied.

a) R is more likely to appear in the first position
b) R is more likely to appear in the third position
 
Example 5: A certain town is serviced by two hospitals. In the larger hospital about 45 babies are born each day. In the smaller hospital about 10 babies are born each day. As you know about 50% of all babies are boys, but the exact percentage varies from day to day. Sometimes it might be higher than 50% and sometimes lower.
For one year each hospital recorded the number of days in which 60% or more of the babies born were boys.
Which hospital do you think recorded the larger number of such days?
a) the larger hospital
b) the smaller hospital
c) the number would be about the same for the two hospitals.
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