Decision Making I: Heuristics Flashcards
Judgment?
Assessment of quantity
Decision?
Act of choosing an option among alternatives
Early Insight into Human Judgment - Just noticeable difference (JND) & Weber-Fechner law (1834)?
Just noticeable difference (JND): The smallest change in quantity that can be noticeable
Weber-Fechner law (1834): The size of the JND is a constant ratio of the reference stimulus
People are more sensitive to proportional differences than absolute differences
Heuristics? Plus Big 3?
Mental short-cuts that allow us to make judgments and decisions quickly
Big 3:
– Availability
– Representativeness
– Affect
Availability?
Are there more words in English that begin with the letter k, or are there more words that have k as their third letter?
~70% said more words begin with k
Ease of retrieval as the basis for judging frequency
Much easier to think of words that begin with a given letter (K) than words that have a given letter in another position
Gives you the false impression that there are many more words with k as the first letter, when in fact there are more words withk as the third letter
____________
Makes us fear events that are rare (plane crashes) and fail to anticipate and thereby prevent more frequent dangers like the development of alcohol poisoning
Representativeness heuristic?
What is the probability that object A belongs to class B?
Probability is related to how much Ais representative of B
Base rate?
Prevalence of an event or characteristic within its population of events or characteristics
How do base rates and representativeness affect judgments?
Ps given base rates and description of member
IV:
– 70% engineers, 30% lawyers
– 30% engineers, 70% lawyers
DV: probability member is engineer
Results?
Results:
– Participants in both groups rated the likelihood that Jack is an engineer to be greater than 90%
– Based their judgments solely on how representative the profile was of an engineer, rather than taking into consideration the proportion of engineers in the sample
Representativeness can reflect how the problems are presented and not….
a lack of competence
Conjunction Fallacy?
Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.
Which is more probable?
A. Linda is a bank teller
B. Linda is a bank teller and is active in the feminist movement
Conjuction of things makes the probability go down
Representativeness and Randomness?
People tend to have difficulty judging probability and randomness
Anchoring & Adjustment?
People make numerical estimates by using a reference as a starting point (anchor) and adjusting from there
