The application of recent advances in the understanding of problem solving to the classroom is reviewed. Current research findings are described, and the instructional validity of these findings is illustrated by a research study of an instructional strategy called novice knowledge engineering. How various instructional strategies serve as knowledge refining agents is shown. Results with six freshmen honors students in college physics are presented. The students who constructed a knowledge base on projectile motion showed that little structuring via differentiation and integration had taken place prior to the knowledge base construction. The acquisition of problem-solving skill through the simultaneous refinement of declarative and procedural knowledge is illustrated, using examples from the best student in the sample. The process of constructing a knowledge base was a viable instructional strategy for refining knowledge while teaching domain specific problem solving. This strategy was a practical application of new research findings. (SLD)