What is needed, then, is similar intensive study of the teacher’s role in problem – solving skill acquisition. Such research could address question like the following; How much time do teachers devote to problem solving? What methods do teachers use? Are the methods similar to those they employ when teaching for other outcome, such as skills and concepts? Do these behaviors tend to be consistent from day to day? How much variance is there among teachers in the method used? When the measurement of learning is restricted to problem – solving achievement made at the expense of learning in other areas? Do teacher who generate large problem – solving gains achieve them uniformly across student aptitude levels?