PSYCH 240 Lecture 19: Lecture 11/30 - Judgment and Decision Making 1
Document Summary
Issues: (a) how should people reason in theory? (b) how do people reason in practice: reasoning taxonomy. Normative vs. descriptive theories: normative theories of probabilistic reasoning. Bayes" theorem: descriptive theories of probabilistic reasoning. If a implies b and a is true, then b is true. 100% airtight - conclusion necessarily follows from premises. All artists are beekeepers and all beekeepers are chemists, so specifically all artists are chemists. It probably rained if the road is wet. Specifically road is wet, so it probably rained. How you should go about doing something e. g. , rules of logic. Descriptive: how people actually reason e. g. , biases, heuristics. Errors that people make and why they make them. You don"t know this for a fact, but it"s consistent with what you"ve seen. Two important pieces to consider for inductive reasoning: How likely the hypothesis is true (independent of evidence) 80% of all women with breast cancer have a positive mammogram result. patient a. c. has a positive mammogram.
