Heuristics Flashcards
define heuristic
process/methos that allows someone to make decisions/udgements
Describe Tversky and Kahnmen (1983) conjunction
pps given story of ‘linda’
31yr single, outspoken, bright, studied philosophy
concerned w/ discrimination, social inustice and participates in antinuclear demonstrations
85% pps report that the probability of linda being a FEMINIST bank teller > ust a bank teller
describe the conunction fallacy
assumed that specific conditions are more probable than a single general one
prob just a bank teller 0.05
prob feminist bank teller 0.95
0.05 x 0.95 = 0.047
prob of two events occuring in conjunction less than or equal to prob of one occuring alone
BUT heuristic suggest more logically representative of her even if mathematically less probable
describe Fiedler (1988)
pps linda story 91% conjunction fallacy THEN pps "100 people fit into the following description.." only 22% commit to conjunction fallacy
descibe Sedlmeier and Gigerenzer (2001)
bayesian reasoning - means of quantifying uncertainty, how knowledge of prior predicts outcome of future
suggest easier in frequency based tan probability based format
why fiedler found lower conjunction fallacy - more representative
describe gamblers fallacy
uses representativemenss heuristic - degree to which a is representative of b
ie believe more likely H H T H T T H than H H H H H
- therefore would lead to betting if something hadnt occured for a while
Describe tversky and Kahenmen (1973) gambling p1
from a sample of 100
‘jack’ written as sterotypical engineer
‘Dick’ written as uninformative
- engineer or lawyer?
half told 30:70 engineer:lawyer & half told 70:30 engineer:lawyer
dick engineer 50% for both groups
Jack reported engineer 90% for both groups
describe the base rate effect
t&k (1973) prob jack is engineer should be lower if 30:70
show we are insensitive to base rates
base rate - representation of world at the time ie more christians
Describe Tversky and Kahenmen (1973) gambling p2
babies born in 2 hospitals - small hospital has 15 births p/day, large hopsital 45 births p/day
which hospital is most likely o have ‘unusual days’ where >60% are boys
- most respond 50:50 (gender 50:50)
BUT - smaller as more likely to represent extremes
- insensitive to base rate sample size
define the availability heuristic
estimation of frequency based on recall ease
report how frequent we think something is based on how easily it comes to mind
describe Tversky and Kahenmen (1973) availability p3
pps think more likely words begin in ‘R’ than have r as third letter in word
words beginning with r come to mind easier
understanding becomes distorted by experience
ie think certain cars all faulty if one is
describe Herbert (2010) availability
availability heurisitc occurs because if something comes to mind quickly then it must be trustworthy
describe Tversky and Koehler (1994) theory
“support theory”
pps. “how likely are you to die on holiday next year” vs. “how likley are you to die on holiday as a result of disease/accident”
- increased subective prob that report more likely to die when cause of death specified
different descriptions of same event give rise to diff judgements
- info more available and attend on less obv aspects
describe Mondel (2005) support
pps report prob terrorist attack
define anchoring
tendency to rely too heavily on first piece of info offered - influence numerical estimate
ie last no of identity no influence how much people pay for a product
describe Englich and Mussweiler (2007) anchoring
prosecutor goal of high 34m sentence or low sentence
influence judges with 15yr experience
sentence av 8m more if high sentence than low for same crime
describe Chapman and banstein (1996) anchoring
personal injury claims
jurors different monetary request for same ovarian cancer caused by prescription drug
$100, $20,000, $5m or $1b
amount award increase with goal increase
explain the law on credit cards
uk credit debt £55.1bn
(2003) treasury select comittee suggest min repayments
describe stewart (2008) anchoring
min repay of credit mock bill £435.76 half recommend £5.42 min half w/o those w/o pay 70% more of bill
strong correlation between min repay and amount repaid - min anchors amount paid
define hindsight bias
outcome of event judged more likely than judgement before it occurs
especially if event has moral/emotional importance
describe Fischoff (1977) hindsight
contestants correct memory of missrecalled answer to match correct answer
how can you investigate hindsight bias
tell one group outcome
dont tell other group
“what would you estimate having not known the bias”
kindsight knowledge give higher estimate of prob & deny knowledge influence
define Casper, benedict and Keller (1988) hindsight
search scenario -
told person guilty (find drugs), not guilty (no drugs) or not told outcome
knowledge of the outcome of the search influenced damage judgements
if guilty
- search more likely legal
-lower damage outcome
-distortion of information in the direction of incriminating the defendant
define recognition heuristic
Gigerenzer and Goldstein
adaptive toolbox” of “fast and frugal” heuristics
ie more easily recognized item will be considered to have a higher value
describe Gigerenzer and Goldstein (1999) recog
american and german students “which american city has largest pop”
62% americans correct
100% germans correct
- sandiego - recognised as has greater news coverage
describe the recog heuristic model
mediator variable - reflects criterion otherwise inaccessible ie no times uni mentioned in papers infers endowment
correlates with:
-recognition - ie correlate between mediator and how much recognise
-criterion - ie actual endowment
recognition validity dependent on criterion
works only when recog correleated with criterion predicted
describe Frosch, Bearman and McClay (2007) recog
pps rank wealth of name on sunday times rich list
recog correlate with wealth
“less is more” - performance better when know less about people
are heuristics bad?
allow us to make quick decisions
rule of thumb important when dont have time to consider all aspects of a situation
avoids other costly and time consuming methods
