Cognition

At an intuitive level, everyone knows what kinds of tasks require problem solving. All problem-solving tasks have a goal, which is a description of what would constitute a solution to the problem. What makes a problem a problem is that the statement of the goal does not act as a cue for its own solution. If your friend asks you to get her a can of diet Coke from the refrigerator in your room, that is not a problem. But, if your friend asks you to get her something to drink, that is a problem statement, because there are several ways that you can formulate and solve your task. Problems vary in the extent to which they are well defined (Newell, 1969; Reitman, 1964; Simon, 1973). In a well-defined problem, such as solving a crossword puzzle or selecting a good chess move, the set of possible actions and the goal are all completely specified. In ill-defined problems there may be uncertainty concerning the possible actions that can be taken, and a variety of solutions may therefore be possible. Despite the slightly negative ring to the term “ill-defined,” many ill-defined problems are very creative tasks, such as painting a picture, designing a house, and writing a story. Virtually all real-life problems, from preparing dinner to losing weight, are ill-defined in some way. In a crime story, both planning a murder and solving it describe solutions to ill-defined problems.

Problem solving is a special case of decision making tasks requiring reasoning, which were described in general in Chapter 14. What all problems have in common is that an ad hoc action must be taken in a novel situation. The neural decision-making system described in Figure 14.1 engages in the reasoning necessary for problem solving.

The process of solving a problem has three major steps (Figure 15.1). The first step is forming an initial representation of the problem. The second and third steps are the same as described for physical action in Chapter 3: planning and execution. The second step is generating and evaluating potential solutions. The third step is executing a procedure to carry out the planned solution that appears to be correct. The execution of a plan has already been described in Chapters 3, 4, and 5. Here, the first and second steps are described.