Representative heuristic 16.422 Probabilities are evaluated by the degree to which A resembles b Problems Prior probability (or base-rate frequency of outcomes Engineers vs lawyers No specific evidence vs. worthless evidence sensitivity to sample size arge vs small hospital Misconceptions of chance Insensitivity to prediction Illusion of validity Stereotypes Regression to the meanRepresentative Heuristic 16.422 • Probabilities are evaluated by the degree to which A resembles B • Problems – Prior probability (or base-rate frequency) of outcomes • Engineers vs. lawyers • No specific evidence vs. worthless evidence – Insensitivity to sample size • Large vs. small hospital – Misconceptions of chance – Insensitivity to prediction – Illusion of validity • Stereotypes – Regression to the mean