An Investigation of the Relation between the Complexity of Problem Structure and Mental Effort

The structure of problem space determines possible strategies that can be used for problem solving and determines the effort of solving a problem. How problem solvers generate problem space when solving illstructured design problems has not been well studied. This paper proposes a method to measure the complexity of problem structuring based on the concept of function decomposition. Data collected from 22 participants, including sketches and verbal protocol reports, were analyzed to investigate the relation between the complexity of problem structuring and mental effort experienced in solving an open-ended design task. The results show that mental effort increases with the complexity of problem structuring.