Chapter 9: Probability Flashcards
1
Q
Baron’s 3 kinds of probability
A
- frequency
- logical
- personal
2
Q
frequency (Baron)
A
- probability judgements are made on the basis of past frequency
- requires knowledge of past frequency in order to work
3
Q
logical (Baron)
A
- works best for exchangeable events
- think about probability mathematically
- 0 = never happens
- 1 = always happens
- probability is in between 0 & 1
4
Q
personal (Baron)
A
- based on personal knowledge
- includes beliefs & frequencies
- can be non-empirical beliefs
5
Q
base rates
A
- rational decision making requires understanding base rates & probability of outcomes
- most ppl don’t know base rates which = hard to make rational decision
6
Q
base rate neglect
A
EXAMPLE
- if there are 100 ppl in room - 70 lawyers, 30 engineers & Ps given description about a person ppl are more likely to say person is engineer & ignore the base rate information
7
Q
Bayes theorem
A
- prescriptive model for how ppl should reason about probabilities
- humans do not match prescriptions of Bayes theorem
8
Q
3 aspects of Bayes theorem
A
- prior probability
- probability that hypothesis is true before consideration of evidence
- P(H) - conditional probability
- probability that particular type of evidence is true if a particular hypothesis is true
- P(E|H) - posterior probability
- probability that a hypothesis is true after considering/observing the evidence
- P(H|E)
9
Q
exchangeable events
A
- logical theories
- ex: Tim Horton’s roll up the rim = you have equal chance as everyone else
10
Q
gambler’s fallacy
A
- confuse appearance of randomness w actual outcomes
- outcome of 1 event does NOT influence the next outcome = events independent
11
Q
conjunctive probabilities
A
- “AND” rule
- what is probability of getting heads AND another heads
- 0.5 x 0.5 = 0.25
12
Q
cumulative probabilities
A
- “OR” rule
- what is probability of getting 2 Hs OR 2 Ts
- 0.25 x 0.25 = 0.50
