BU 3 6 Rule: A card with a vowel (p) will have an even number on the other side (q). Which card or cards should be turned over to test the rule? People do pretty well applying modus ponens but have trouble applying modus tollens. (The problem is easier when real world examples are used.) ~ p p ~ q q

Heuristics Representativeness Availability Simulation Problem solving Gestalt influence Insight Functional fixedness Einstellung Analogies (see Goldstein)

Heuristics Representativeness Availability Simulation

Heuristic general rule (“rule of thumb”) lacks details works much of the time but prone to error Algorithm specific rule or procedure (formula) often detailed, intricate highly accurate (gives correct answer as long as applied correctly)

Heuristics Representativeness LOTTO Which set of numbers is more likely to be the winning combination?

Heuristics Representativeness (1) people try to apply their knowledge of a process to generate possible answers or judge the likelihood of an event LOTTO drawing: random process; people pick a number that appears more random (less orderly) This error reflects an insensitivity to sample size.

Heuristics Representativeness (2) people apply their knowledge of a very large sample (population) to an event, focusing on the similarities Stereotypes (very general info about a group) irrelevant information (that fits a stereotype) can influence judgements – to the extent that important, relevant info is overlooked

Stereotypes 80 people in room 60 medical doctors, 20 academics H. R. is dressed in a coat and tie. His appearance is tidy. He is personable, and his communication is direct. He enjoys playing squash and likes driving BMWs. L. J. is dressed in pants and a loose-fitting shirt. His appearance is a bit unkempt. He is personable, and his communication is long-winded. He enjoys reading mysteries and riding bicycles. What is the probability that H. R. is a medical doctor? What is the probability that L. J. is a medical doctor?

Stereotypes 80 people in room 60 medical doctors 20 academics The extra info biases one’s estimate of an individual being a doctor or an academic. (Basically, info that fits with a stereotype is misapplied to an individual.)

Heuristics Representativeness Availability Simulation

Heuristics Availability highly accessible info influences judgments Frequency bias memory for relative frequencies of different types of info can be quite good under controlled conditions in the real world, though, a person’s views can influence how he/she encodes events confirmation bias; frequencies of events in memory may be inaccurate

Familiarity bias how familiar info is influences judgements (research often done with famous and nonfamous names); people overestimate likelihoods based on fame/familiarity Salience (Vividness) bias big events (or events with lots of remembered details) influence judgments; people overestimate likelihoods based on big events

Heuristics Representativeness Availability Simulation

Heuristics Simulation application of a change in a sequence of events shifts the outcome (or probability for that outcome) of the event Undoing heuristic typically a less usual event is changed to a more usual event; downhill change far less likely, a usual event is changed to a less usual event; uphill change

Heuristics Simulation application of a change in a sequence of events shifts the outcome (or probability for that outcome) of the event Focus rule changes more likely to be made around the subject of focus

Heuristics Simulation application of a change in a sequence of events shifts the outcome (or probability for that outcome) of the event Hindsight event seems more likely after the fact Anticipation of events thought of favourable outcomes blinds us to negative outcomes; leads to overestimation of a positive outcome

Heuristics Representativeness Availability Simulation Problem solving Gestalt influence Insight Functional fixedness Einstellung Analogies

Problem solving Gestalt influence early research on “insight” -- chimp Later research on humans subjective experience of insight different from other problem solving solution comes all of a sudden in insight solution feels like it comes more gradually with other problems (e.g., algebra) (see “warm” ratings in Goldstein)

Draw a continuous line with no curves and no more than 4 segments to connect all of the dots

Draw a continuous line with no curves and no more than 4 segments to connect all of the dots

Draw a continuous line with no curves and no more than 4 segments to connect all of the dots

Draw a continuous line with no curves and no more than 4 segments to connect all of the dots

Draw a continuous line with no curves and no more than 4 segments to connect all of the dots

Problem solving Problems associated with problem solving Functional fixedness (solution) is slowed or prevented by a focus on objects usual function a solution may require the novel application of an object

Problem solving Need 100 liters of H 2 O. Have 3 containers of which the capacity is known Container A = 21 liters Container B = 127 liters Container C = 3 liters How to measure out 100 liters?

Problem solving Need 100 liters of H 2 O Have 3 containers of which the capacity is known Container A = 21 liters Container B = 127 liters Container C = 3 liters How to measure out 100 liters? B – C – C – A

Problem solving Need 18 liters of H 2 O Have 3 containers of which the capacity is known Container A = 15 liters Container B = 39 liters Container C = 3 liters How to measure out 18 liters?

Problem solving Need 18 liters of H 2 O Have 3 containers of which the capacity is known Container A = 15 liters Container B = 39 liters Container C = 3 liters How to measure out 18 liters? B – C – C – A

Problem solving Need 22 liters of H 2 O Have 3 containers of which the capacity is known Container A = 18 liters Container B = 48 liters Container C = 4 liters How to measure out 22 liters?

Problem solving Need 22 liters of H 2 O Have 3 containers of which the capacity is known Container A = 18 liters Container B = 48 liters Container C = 4 liters How to measure out 22 liters? B – C – C – A

Problem solving Need 25 liters of H 2 O Have 3 containers of which the capacity is known Container A = 28 liters Container B = 76 liters Container C = 3 liters How to measure out 25 liters?

Problem solving Einstellung – “mind set” approach to a problem Set effects (or negative set effects) use of a set approach impedes performance

Heuristics Representativeness Availability Simulation Problem solving Gestalt influence Insight Functional fixedness Einstellung Analogies (see Goldstein)

End Have a good day! Thank you for a terrific trimester!