Dorothea P. Simon and Herbert A. Simon
In giving students practice in solving textbook problems, our objective is to help them acquire skills they will be able to apply when they encounter problems in the real world. Transfer of skills to real-world problems requires both that the skills be relevant to the problem and that they be recognized as relevant. But textbook problems are highly structured--all or almost all irrelevancies are stripped from them, and their solutions usually involve two or three equations or concepts just studied by the class. Real-world problems, on the other hand, come to the problem solver poorly defined--surrounded by a vast mass of information that is possibly relevant but often irrelevant.
Awareness of the cognitive processes involved in solving both kinds of problems may help us plan instruction that can help students bridge the gap between "book larnin'" and real-world problem solving. One possible technique for bridging this gap, which has been suggested by our recent work in this area, is to give students practice with problems that have some of the ambiguity and complexity of structure of the latter.
In order to gain some understanding of how people approach relatively complex, ill-structured problems, we constructed such a problem and asked a number of subjects to solve it while thinking aloud. We discuss here primarily the tape-recorded thinking-aloud protocols of two subjects who were experts in the domain of the problem--one a professional physicist, the other a chemical engineer--whose protocols, as we shall see, take strikingly different paths. Our interest lies in understanding why this was so and what lessons can be drawn for the skills required to solve ill-structured problems that are meant to reflect realworld complexity.
The problem, which we entitled "A Desperate Plight," is as follows:
When Tom Swift and his crew were shipwrecked on the moon, they were able to salvage oxygen supplies ample for a lifetime, several miles' length of aluminum pipe, a solar-powered water pump with variable capacity, and a sack of seed corn. They immediately set about to see what could be found by way of water and food supplies.