The main objective of this study is to uncover the differences in the programming behavior between methodology designers and methodology users. We conducted an experiment with methodology designers who have invented one of the major object-oriented methodologies and programmers who have used the methodology for their projects. Concurrent verbal protocols were analyzed based on a theoretical framework which views programming as search in four problem spaces: Representation, rule, instance, and paradigm. In programming, the main problem spaces are the representation and the rule spaces, while the paradigm and instance spaces are the supporting spaces. The results of the experiment show that differences in the supporting space produced different search behavior in the main problem spaces, which in turn resulted in diierent final programs and performance.