Lecture 12 - Judgements, Decision and Reasoning Flashcards
what is a heuristic?
simple procedure used to find adequate but often imperfect answers to difficult questions
who is KT?
Daniel Kahneman and Amos Tversky
what is bounded rationality?
theory that humans reason and choose rationally, but only within the constraints imposed by their limited search and computational capacities
what is satisficing?
using experience to construct an expectation of how good a solution we might reasonable achieve and halting search as soon as a solution is reached that meets the expectation
what did paul meehl find
that clinical prediction performs very poorly relative to statistical prediction and that it overweights case characteristics and underweights base rates
what are the characteristics of system 1?
intuitive, fast, nonconscious, automatic
what are the characteristics of system 2?
reflective, slow, conscious, controlled
how do system 1 and 2 interact?
- system 2 kicks in when system 1 is unable to solve/interpret/understand stimuli
- system 1 feeds system 2 and 2 normally takes this on apart from when there is something obscure not taken on by 1
- NB, 2 is not actually that slow as it is responsible for control, eg control of not saying something we shouldn’t
how can we improve system’s 2 intervention?
- provide rewards to motivate checking of intuitive impressions
- reduce cog load
- increase metacog difficulty (although this one is sceptical)
what is the proposed mechanism of system 1?
question substitution:
as seeking answer to complex question is hard, system 1 overwrites the question to make it an easier question it thinks is related, substituting an easy to compute feature for a hard to compute feature
what are the 3 general purpose heuristics?
- representativeness
- availability
- affect
what is the representativeness Heuristic?
give example
probability judgements are substituted with assessments of resemblance… the likelihood that X is Y is substituted with the “degree to which X looks like Y”
Eg, how likely is it that tom is a computer science student is substituted with how much does time resemble a comp science student?
what is the core of the conjunction fallacy?
that people substitute a question about probability with similarity
what are the biases related to representativeness heuristic?
- conjunction fallacy (bank teller/fem example)
- insensitivity to sample size (kids in hospital)
- misperceptions of randomness (ipod shuffle example)
- belief in the law of small numbers (mistaken confidence in adequacy of small samples representative of pop)
- hot hand fallacy
- base rate neglect (engineer v lawyer guessing)
what is the availability heuristic?
factors which come to mind easily are assigned more weight in the formulation of judgments. we judge the likelihood/frequency of an event by the ease with which instances come to mind
example of availability heuristic?
hollywood v train drives divorce rates? we think hollywood have higher divorce rates as we are exposed to that information more often
what are the biases related to availability heuristic?
- effectiveness of search set (eg, scrabble, “ing” v “n” words)
- egocentric bias (husband v wife rating their contribution to various activities in relationship - not self serving)
- outcome (decision with positive outcome is rated as superior)
what does schwarz suggest determines our availability? which study proposed this?
our subjective experience of the ease of recall
asking participants to either come up with 6 or 12 examples of assertiveness… those who had to get 12 struggled and stopped at 6, thus thinking they were not assertive, whereas those who were asked to come up with 6 assertive examples then viewed themselves as quite assertive
what is the affect heuristic?
give eg
judgements are made in accordance with the intensity of the emotion felt
eg, how large are the benefits of nuclear power? and you substitute in a response as to how you feel about nuclear power
what are the biases related to affect heuristic?
- negative risk/benefit correlation (benefit/risk of nuclear power leads to inferring the other (risk/benefit) of it)
- insensitivity to numbers (saving % of 150 lives was more supported than saving 150 lives)
what is a so called heuristic?
anchoring heuristic
what is the anchoring “heuristic”?
when estimating quantities, people start with an intuitive reference point (anchor) and make adjustments to it
what is an example of the anchoring heuristic
1x2x3 etc gets smaller estimate than 3x2x1 etc
what were the 3 critiques of KT’s work
- KT’s biases lack external validity
- have been vaguely theorised/specified and there has been a lack of formal modelling
- overstates the problems caused by computational limits of our brains
what are some examples of the critique: 1. KT’s biases lack external validity
minor changes in wording/context could sometimes debias people, eg
- eliciting frequencies rather than probabilities
- emphasising the role of random sampling
what is an example of the critique: KT’s work overstates the problems caused by computational limits of our brains
complex methods won’t necessarily outperform simple one
the fast and frugal methods can be better
what is an example of a fast and frugal method?
recognition heuristic
what is the recognition heuristic
give eg
theory that you may actually be correct if you recognise one object and not the other which leads you to determine it has the higher value
eg: which city has more inhabitants question
- those who recognises only one were more often correct
what heuristic might come into play if “both cities” are recognised?
“Take the best”
what is the “Take the best” heuristic?
look up cues in order of their validity, stop search when ev for one object (city featured in film) but not the other is found
