Probability Judgmints by Preschool Children: Task Conditions and Performance

Two age- and sex-matched groups of 16 preschoolers made probability judgments under two conditions: Condition P (similar to Piaget's techniques) and Condition DM (a decision-making procedure). P and DM differed in display, type of judgment required, and controls for color preference. In both conditions, the trial sequence systematically varied: (a) probability under consideration, (b) number of elements in the distribution under each probability, and (c) predominance of preferred and nonpreferred colors. The mean number of correct responses was significantly greater in DM than it was in P. Analysis of errors indicated that decisions based upon number instead of proportion in DM and decisions based upon color preference instead of color expectation in P accounted for a significant number of incorrect responses. High scoring Ss made systematic errors between probability conditions, with the number of errors increasing as the probability under consideration approached .50 in both P and DM. The number of items in the distributions did not significantly affect judgments.