Proceedings of the Annual Meeting of the Cognitive Science Society

The action order of most everyday activities is only weaklyconstrained: When setting the table, for example, the orderin which the items are placed on the table does not matter ifall required items are on the table eventually. Little is knownabout how humans deal with weakly constrained sequences.Consistent with research on local optimality of human behav-ior and the “law of less work”, we propose that the order ofweakly constrained sequences is not chosen arbitrarily but dueto preferences, with the overall goal to minimize cognitive andphysical effort. We implement and validate a stepwise-optimalmodel for table setting, revealing ordering preferences basedon distance, functional relations between items, and reachabil-ity. The model’s success has implications concerning actionorganization in weakly constrained sequences as well as con-trol of action sequences and provides further evidence on thequestion of global vs. local optimality of human cognition.