16.422 Human Supervisory Control Judgment Under Uncertainty Heuristics biases Massachusetts Institute of Technology
16.422 Human Supervisory Control Judgment Under Uncertainty: Heuristics & Biases
The Uncertain state of the World 16.422 Probabilit Theory Objective Subjective Probability Probability SEU ·MAUT Axiomatic Statistical · Bayesian Nets Probability Probability
The Uncertain State of the World 16.422 Probability Theory Objective Probability Subjective Probability Statistical Probability Axiomatic Probability • S E U • M A U T • Bayesian Nets
Subjective Assessment 16.422 Subjective assessment of probabilities is akin to assessment of size and distance Perception versus expectation Heuristics are useful but can be misleading
Subjective Assessment 16.422 • Subjective assessment of probabilities is akin to assessment of size and distance • Perception versus expectation • Heuristics are useful but can be misleading
The ames room 16.422 (Image removed due to copyright considerations. http://psylux.psych.tu-dresden.de/il/kaw/diverses%20material/www.illusionworks.com/html/aMes_room.html
The Ames Room 16.422 http://psylux.psych.tu-dresden.de/i1/kaw/diverses%20Material/www.illusionworks.com/html/ames_room.html (Image removed due to copyright considerations.)
Expectations Can Fool You 16.422 Checker- shadow illusion The squares marked A and B are the same shade of gray Edward H. Adelson These checkershadow images may be reproduced and distributed freely. @1995, Edward H Adelson. Used with permission
Expectations Can Fool You… 16.422 These checkershadow images may be reproduced and distributed freely. ©1995, Edward H. Adelson. Used with permission
Human estimation cue Integration 16.422 Humans as intuitive statisticians Good at estimating means, reasonably good at mid-range roportions · Not good on the tails Not so good at estimating variances and correlations Also not good at extrapolating non-linear trends Underestimate exponential growth Cue assimilation issues Missing Information overload Salience Underestimate cues that require calculation The need for heuristics
Human Estimation & Cue Integration 16.422 • Humans as intuitive statisticians – Good at estimating means, reasonably good at mid-range proportions • Not good on the tails – Not so good at estimating variances and correlations – Also not good at extrapolating non-linear trends • Underestimate exponential growth • Cue assimilation issues – Missing – Information overload – S a l i e n c e • Underestimate cues that requi re calculation – The need for heuristics
As-if heuristic 16.422 Cues are equally weighted and differential weights are not considered Regression to the mean Reliability of cues Letters of recommendation -content v tone Humans are poor intuitive or clinical predictors as compared to computers Multiple cues of different information value Cognitive parsimony Humans tend to reduce load on working memory Avoid processing of cues that require mental calculatⅰon
As-if Heuristic 16.422 • Cues are equally weighted and differential weights are not considered – Regression to the mean – Reliability of cues – Letters of recommendation – content v. tone • Humans are poor intuitive or clinical predictors as compared to computers – Multiple cues of different information value • Cognitive parsimony – Humans tend to reduce load on working memory. – Avoid processing of cues that require mental calculation
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 mean
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 – Insensitivity to sample size • Large vs. small hospital – Misconceptions of chance – Insensitivity to prediction – Illusion of validity • Stereotypes – Regression to the mean
availability heuristic 16.422 Assessing probability or frequency bases on information that is most readily recalled Problems Retrievability of instances Familiarity, salience, recency -driven by experience Effectiveness of a search set Searching for solutions in your long term memory Imagability · Simplicity · Decision making & alternatives Illusory Correlation How frequently two events co-occur Effectiveness of search set .. abstract words as opposed to concrete
Availability Heuristic 16.422 • Assessing probability or frequency bases on information that is most readily recalled • Problems: – Retrievability of instances • Familiarity, salience, recency – driven by experience – Effectiveness of a search set • Searching for solutions in your long term memory – Imaginability • Simplicity • Decision making & alternatives – Illusory Correlation • How frequently two events co-occur Effectiveness of search set….abstract words as opposed to concrete
Adjustment &anchoring Heuristic 16.422 People start with an initial guess and adjust answers based on available information Problems Insufficient adjustment 1x2X3x4x5x6X7x8V. 8x7x6x5x4x3x2x1 ·512.2250.40320 Evaluation of simple, conjunctive(and)& disjunctive(or) events Overestimate conjunctive underestimate disjunctive Ordering matters Assessment of subjective probability distribution Overly narrow confidence intervals Simple- draw red from bag 50/50 red and white Conjunctive -draw seven successive reds from a bag 90/10 Disjunctive -draw a red at least once in seven tries from a bag 10/90 0/48522
Adjustment &Anchoring Heuristic 16.422 • People start with an initial guess and adjust answers based on available information • Problems – Insufficient adjustment • 1x2x3x4x5x6x7x8 v. 8x7x6x5x4x3x2x1 • 512, 2250, 40320 – Evaluation of simple, conjunctive (and) & disjunctive (or) events • Overestimate conjunctive, underestimate disjunctive – Ordering matters – Assessment of subjective probability distribution • Overly narrow confidence intervals Simple – draw red from bag 50/50 red and white Conjunctive – draw seven successive reds from a bag 90/10 Disjunctive – draw a red at least once in seven tries from a bag 10/90 .50/.48/.522
