The subjective impression that one situation is similar to another situation. People often judge probability by the degree to which A resembles B. In other words, when aspects of a situation seem similar to those of another situation, they are more likely to predict that they will show similar responses to change. They do this even when they believe that the similar characteristics are irrelevant. Tversky and Kahneman (1982) use the following example to reveal this tendency:
“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 antinuclear demonstrations. Please check off the most likely alternative:
□ Linda is a bank teller.
□ Linda is a bank teller and is active in the feminist movement.”
Nearly 90% of the subjects (n = 86) thought that Linda was more likely to be a bank teller and a feminist than to be a bank teller. Representativeness can create problems in using expert opinions or intentions surveys. It is useful in writing scenarios. See conjunction fallacy.