Covariation Judgment: Improving Rule Use among Children, Adolescents, and Adults

Abstract

SHAKLEE, HARRIET; HOLT, PAUL; ELEK, SUSAN; and HALL, LAURIE. Covariation Judgment: Improving Rule Use among Children, Adolescents, and Adults. CHILD DEVELOPMENT, 1988, 59, 755-768. People improve in strategies of covariation judgment in later childhood and adolescence, but most people never acquire use of the optimal rule of covariation judgment: the conditional probability rule. In the present studies, training paradigms were used to pinpoint key obstacles to covariation judgment accuracy among children, adolescents, and adults. In Experiment 1, college subjects were able to use the conditional probability rule when simply shown how to compose the relevant conditional probabilities for comparison, suggesting that they were fully competent to use the rule, but had never discovered which information was necessary for the judgment. Junior high subjects, in contrast, needed to learn how to compare the 2 conditional probabilities before they could use the conditional probability rule. However, even with this comparison training, a majority of junior high subjects failed to learn the rule. In a second study, fourththrough eighth-grade children could be taught to compare 2 sums in the sum-of-diagonals rule at ages when they would have had difficulty comparing the 2 ratios involved in the conditional probability rule. Further analyses indicate likely reasons for the special difficulty of ratio comparisons for children and adolescents.