Kahneman and Tversky (1974)

Question 1

Aim

Answer 1

To investigate the effect of anchoring on estimate the value of a mathematics problem.

Question 2

Method

Answer 2

• In this study, high school students were used as participants. Participants in the “ascending condition” were asked to quickly estimate the value of
  1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 in five seconds.
• Those in the “descending condition” were asked to quickly estimate the value of
  8 X 7 X 6 X 5 X 4 X 3 X 2 X 1.
• Since we read from left to right, the researchers assumed that group 1 would use “1” as an anchor and predict a lower value that the group that started with “8” as the anchor. The expectation was that the first number seen would bias the estimate of the value by the participant.

Question 3

Results

Answer 3

The researchers found that the median for the ascending group was 512; the median for the descending group was 2250. The actual value is 40320.

Question 4

Conclusion

Answer 4

“People make estimates by starting from an initial value that is adjusted to yield the final answer,” - Amos Tversky and Daniel Kahneman. “The initial value, or starting point, may be suggested by the formulation of the problem, or it may be the result of a partial computation. In either case, adjustments are typically insufficient. That is, different starting points yield different estimates, which are biased toward the initial values.“

Question 5

Outline strengths.

Answer 5

• This study provides evidence for how reliance on heuristics and the prevalence of biases when intuitive (System 1) thinking is used by people in everyday life as well as in research in the human sciences.
• The study is a very simple experiment that is easily replicated, allowing us to establish the reliability of the results. The study is highly controlled and has high internal validity. It can be inferred that the anchor was the cause of the higher (or lower) estimates by the students.

Question 6

Outline limitations.

Answer 6

• This study provides evidence for how reliance on heuristics and the prevalence of biases when intuitive (System 1) thinking is used by people in everyday life as well as in research in the human sciences.
• The study is a very simple experiment that is easily replicated, allowing us to establish the reliability of the results. The study is highly controlled and has high internal validity. It can be inferred that the anchor was the cause of the higher (or lower) estimates by the students.