Heuristics
In the early 1970's, Tversky and Kahneman argued that humans make use
of cognitive heuristics (short cuts) which reduce the complexity of making probabilistic judgments. These are very useful but can lead to systematic errors.
You should be familiar with the following heuristics (be warned this is complicated territory and we welcome any simplifications you can suggest):-
Representativeness refers to making an uncertainty judgment on the basis of 'the degree to which it is (i) similar in essential properties to its parent population and (ii) reflects the salient features of the process by which it is generated.
For example if you were told that Steve is a very shy and withdrawn but helpful man with little interest in people you may assume he is a librarian rather than say for instance a doctor. This may be true most of the time.
Availability is used to estimate 'frequency or probability by the ease with which instances or associations come to mind.
For example, exposure to media about violent crime will tend to inflate our estimate of the overall frequency of violent crime.
Anchoring-and-adjustment involves 'starting from an initial value that is adjusted to yield the final answer.
For example in one study a mock jury was told to contemplate the harshest verdict first. The final verdict was found to be relatively harsh.
Framing influences how we make descision. Choices are often made depending on how information is presented (framed) rather than for the correct reason.
of cognitive heuristics (short cuts) which reduce the complexity of making probabilistic judgments. These are very useful but can lead to systematic errors.
You should be familiar with the following heuristics (be warned this is complicated territory and we welcome any simplifications you can suggest):-
Representativeness refers to making an uncertainty judgment on the basis of 'the degree to which it is (i) similar in essential properties to its parent population and (ii) reflects the salient features of the process by which it is generated.
For example if you were told that Steve is a very shy and withdrawn but helpful man with little interest in people you may assume he is a librarian rather than say for instance a doctor. This may be true most of the time.
Availability is used to estimate 'frequency or probability by the ease with which instances or associations come to mind.
For example, exposure to media about violent crime will tend to inflate our estimate of the overall frequency of violent crime.
Anchoring-and-adjustment involves 'starting from an initial value that is adjusted to yield the final answer.
For example in one study a mock jury was told to contemplate the harshest verdict first. The final verdict was found to be relatively harsh.
Framing influences how we make descision. Choices are often made depending on how information is presented (framed) rather than for the correct reason.
