[Patterns and Practices] Patterns have been around conceptually since the late 1970s when Christopher Alexander wrote The Timeless Way of Building and A Pattern Language, which helped spark the pattern movement that was later applied to software engineering in the 1990s. Although Alexander and the software patterns community have created quite a stir around the construction of a pattern language, testing such a language has been largely neglected. Testing has a different agenda: to substantiate designs and implementations based on certain criteria and according to a methodology. Hence, following Microsoft Solution Framework (MSF) processes, the test team has developed a formal testing methodology and testing criteria, which are distilled from best practices found in the larger patterns community. This document describes the testing methodology that the test team developed and applied to the new field of testing software patterns.