Preschoolers use probabilistic evidence to flexibly change or maintain expectations on an active search task.

This study investigated 3- to 5-year-olds' (N = 64, 37 girls, 62.5% White, data collected between 2021-2022) ability to use probabilistic information gleaned through active search to appropriately change or maintain expectations. In an online fishing game, children first learned that one of two ponds was good for catching fish. During a subsequent testing phase, children searched the ponds for fish. Half saw outcomes that were probabilistically consistent with training, and the other half saw outcomes that were probabilistically inconsistent. Children in the Inconsistent condition adapted their search strategies, showing evidence of changing their expectations. Those in the Consistent condition maintained their initial search strategy. Trial-by-trial analyses suggested that children used a combination of heuristic and information integration strategies to guide their search behavior.