PHI 2100 01 Review for Exam 2 Gilovich 1 What is the Cluster Illusion Give an example of someone being affected by it Cluster Illusion is the intuition that random events such as coin flips should alternate between heads and tails more than they do o When a random distribution seems to have too many clusters or streaks of consecutive outcomes to be truly random o Random distributions seem to us to have too many clusters or streaks of consecutive outcomes of the same type a Have difficulty accepting their true origins o The term illusion is well chosen a Not eliminated by repeated examination o Stems from a form of over generalization o We expect the correct proportion of heads and tails or hits and misses to be present a Globally in a long sequence b Locally in each of its parts o 8 hits in 11 shots does not look random a Deviates from 50 50 split b Short sequences split is not unlikely Who is affected by it o People gambling o Hot Hand Fallacy fallacious belief that a person who has experienced success with a random event has a greater chance of further success in additional attempts a EX Basketball players 2 What is the Law of Large Numbers What is the problem with accepting a fictional law of small numbers Law of Large Numbers LLN a theorem that describes the result of performing the same experiment a large number of times o The average of the results obtained from a large number of trials should be close to the expected value a Tend to become closer as more trials are performed o Patterns show up in the long run o Important because it guarantees stable long term results for the averages of random events o EX A casino may lose money in a single spin of the roulette wheel a Its earnings will tend towards a predictable percentage over a large number of spins b Any winning streak by a player will eventually be overcome by the parameters of the game What is the problem with law of small numbers Law of small numbers informal fallacy of faulty generalization by reaching an inductive generalization based on insufficient evidence a Essentially making a hasty conclusion without considering all of the variables b Basing broad conclusions regarding the statistics of a survey from a small sample group that fails to sufficiently represent an entire population People think a pattern that shows up in the long run should be reflected in the short run 3 Define Regression to the Mean Give an example of when people tend to ignore regression to the mean Regression to the Mean For imperfectly correlated facts or events an extreme value on one tends to be matched with less extreme value on the other o If a variable is extreme on its first measurement it will tend to be closer to the average on its second measurement and paradoxically if it is extreme on its second measurement it will tend to have been closer to the average on its first o EX Regression Fallacy o Tendency to make non regressive predictions can be attributed to judgment by representativeness o The better the prediction the less regressive one needs to be Two problems occur o People tend to be insufficiently conservative or regressive when making predictions a EX Company has a good year and expects to earn as much the next year b EX Parents expect their child whom did well in school to do as well the next year o Regression Fallacy c EX Predicting GPA s with actual grades and humor 4 What is the Regression Fallacy Regression Fallacy tendency to fail to recognize statistical regression when it occurs and to instead explain the observed phenomena with superfluous and often complicated casual theories o By developing elaborate explanations for phenomena that are the predictable result of statistical regression people form spurious beliefs about phenomena and casual relations in everyday life Sports Illustrated jinx is one such fallacy o Individuals don t like being pictured on Sports Illustrated because it is believed to spell doom for whatever success was responsible for landing them on the cover o However we should expect an extraordinary performance to be followed by a somewhat less extraordinary performance o Athletes appear on the cover when their performance is extraordinary so it should be expected that their performance would drop off Plays a role in shaping parents and teachers beliefs about the relative effectiveness of reward and punishment in producing desired behavior and learning Regression guarantees that really good performances will deteriorate Bad performances are followed by improvement a Rewards are given after good performances b Reward is ineffective or counter productive c Punishment will appear to be beneficial reward the administration of punishment a EX Arrival times for students at work b Arrival times improved when punished o Regression effects serve to punish the administration of reward and to Regression effects teach us misleading lessons about the relative effectiveness of reward and punishment 5 What is Representative Bias Give an example of how someone might be affected by it Representative Bias occurs when people s judgments about probabilities involving items A and B are affected by the resemblance between A and B o Like goes with like o We expect effects to look like their causes o EX Attribute stomach ache to spicy food rather than bland food Can be valid and helpful because objects instances and categories that go together often do share a resemblance o Overapplication of representativeness is problematic EX If someone loves Chinese poetry are they more likely to be a business major or Chinese poetry major o Business Major a Because there are more business majors than Chinese poetry majors b People mays succumb to representative bias and think the person is Chinese Poetry major just for the sole reason that they enjoy Chinese Poetry c Completely ignores base rates EX Expecting a librarian to look and act like a librarian o We expect instances to look like the categories of which they are members 6 What are ad hoc explanations Give an example of an ad hoc explanation Ad hoc explanations are ones that are hastily constructed to support or explain something without any underlying sense or logical framework Because of the haste and lack of consistent framework the explanation is likely to contradict existing thought or other arguments o EX Many alternative medicines have been disproved or shown to be nothing more than placebos but believers will make up excuses as to why the controlled and properly