1. How do we reason and solve problems? Psychological factors in solving problems Varieties of problems Algorithms and heuristics Barriers and strategies Psychological factors in formal reasoning Syllogisms The “troublesome” conditionals Psychological factors in informal reasoning Human biases

2. Greeno’s categorization of problems: 1. Problems of inducing or revealing structure 2. Problems of arrangement 3. Problems of transformation

3. Syllogisms: two or more premises and a conclusion Premise 1: All men are mortal. Premise 2: Socrates is a man. Conclusion: Socrates is mortal. Common pitfalls: Incorrect premises Violations of rules of logic

4. Particular difficulties with conditional statements: If it is raining, then Carol carries an umbrella. It is raining. Conclusion: Therefore Carol carries an umbrella. 1. If it is raining, then Carol carries an umbrella. Carol does not carry an umbrella. Conclusion: Therefore it is not raining. 3. If it is raining, then Carol carries an umbrella. Carol carries an umbrella. Conclusion: Therefore it is raining. 2.

5. Wason Four-Card Test (abstract version) EF 47 “Each card has a letter on one side and a number on the other. The task is to test the following hypothesis—if a card has a vowel on one side, then it has an even number on the other side. Choose which card or cards you want to flip over.” 2 1 2 1 A B A B Possible flip side:

6. Wason Four-Card Test (concrete version) Is at least 19 “Each card has what the person is drinking on one side and the person’s age on the other. The task is to test the following hypothesis—if a person is drinking beer, then that person must be at least 19 years old. Choose which card or cards you want to flip over.” 19 <19 19 <19 beer coke beer coke Possible flip side: beer coke>19 <19

7. Confirmation bias Overuse of representativeness Availability bias Framing effects

8. You had decided to go to a concert and had already bought a $50 ticket. As you enter the theatre, you realize you have lost your ticket. You can’t remember the seat number so you can’t prove that you bought the ticket. Assuming you have enough cash, would you buy a new $50 ticket? a. b. A simple “framing” effect