Probability cognition in judging the probabilities of binary-event-sequence.
Toshiharu Kasai · The Japanese journal of psychology · 1988
The fallacious probability judgment of binary event sequence (Bernoulli sequence) was studied in terms of probability cognition. The categorizational fallacy hypothesis (Kasai, 1982) asserts that people tend to respond with a categorical probability (the probability of occurrence of the category to which a given instance belongs) even when they are asked to answer the individual probability of instance. In Exp. 1, 46 undergraduates were instructed to make the paired comparison of probability among 15 binary sequences of length 6. Their modal judgments were compared with the theoretical predictions based on the ideal probability distributions and also with the predictions from the subjective distributions which were generated by 24 undergraduates in Exp. 2. The results confirmed the predictions, particularly those based on the subjective distributions (maximum hit rate 82.9%). Based on these results it was concluded that the subjects judged the likelihood of each sequence in terms of categorical probability rather than the required individual probability, and it was suggested that the fallacious judgment is derived from the cognitive process of abstracting and symbolizing.