Proceedings of the Annual Meeting of the Cognitive Science Society

Physical assembly is a difficult planning problem. Humans do it efficiently by breaking large problems into smaller, easier to solve portions. What governs which portions are chosen? We present a model that predicts that humans break assembly problems down to minimize cognitive costs. We test this by asking participants to choose which part of a tower they want to build next. Participants reliably choose the easier to solve subgoal out of two otherwise similar options. Beyond the immediate cognitive cost, participants also consider how difficult the rest of the tower will be to solve. A model that takes into account near-future cognitive costs best predicts participants' choices. These findings show that humans can estimate how difficult solving a subgoal will be, and that they choose subgoals to minimize immediate and future cognitive costs. These results help explain how humans make efficient use of cognitive resources to solve complex planning problems.