The development of forward search planning in preschoolers.

Previous evidence suggesting that young children have some ability to plan by means of forward search suffers from typical findings that individual performance is inconsistent and group performance is low. In the present study, evidence is sought that children's imperfect performance results from unstable execution of the correct component processes of forward search, rather than from use of flawed or incomplete rules. 4- and 5-year-olds participated in a route-planning task in which they collected items from several locations in a large space. Incorrect routes required having to backtrack to locations previously visited. Forward search in this task required 3 component processes: representing a possible route, evaluating the route for backtracking, and if necessary, repeating the procedure for an alternate route. Evidence from stochastic parameter estimation and from children's self-corrections and explanations showed that 5-year-olds engaged in forward search, but that 4-year-olds used only a rudimentary form of forward search. Developmental changes involved children's ability to foresee and avoid backtracking, to consider alternate routes, and to spontaneously self-correct errors. Results are discussed in terms of implications for our understanding of the structure and development of early problem-solving skills in general.