Overview, Case Study (OCS) Physics is an effort to integrate recent results from physics education research into instruction for introductory university physics courses that emphasize problem solving. Students actively construct a knowledge hierarchy on a foundation of qualitative understanding. They analyze physical processes and problems using methods similar to those used by experienced scientists. Students receive repeated exposure to concepts in a variety of contexts over an extended time interval. Preliminary trials of OCS Physics have produced promising gains in student qualitative understanding, in their ability to solve problems, and in their ability to form and access a knowledge hierarchy.