The document reports on an experiment evaluating the use of Content Ontology Design Patterns (ODPs) and the eXtreme Design (XD) methodology and tools. The experiment confirmed previous findings that Content ODPs improve ontology quality and reduce common mistakes. It also found that the XD tools support reuse of ODPs and that the XD methodology further decreases mistakes through its test-driven approach. Areas for future work include improving collaboration support and evaluating the methodology on other tasks.