Problem solving has long been recognized as an important cognitive activity, important in relation to educational theory and practice as found in the classroom and important more generally to the issues that confront people in daily living (cf. Dewey, 1916). Thus, there are two, somewhat related ways in which problem solving has been viewed as critical to education. First, problem solving has been considered as part of the learning of subject matter, especially in mathematics and the physical sciences. Problem-solving exercises, moreover, have two functions. One is the testing function: problem solving is used to determine what the student has or has not learned. The other is the teaching function: working problems not only tells whether the student understands the subject matter, but also provides for a better understanding of that subject matter.