Quality has emerged as a key issue in the development and deployment of software products (Haag et al. 1996; Prahalad and Krishnan 1999; Yourdon 1992). As software products play an increasingly critical role in supporting strategic business initiatives, it is important that these products function correctly and according to users’ specifications. The costs of poor software quality (in terms of reduced productivity, downtime, customer dissatisfaction, and injury) can be enormous. For example, the Help Desk Institute, an industry group based in Denver, estimates that in 1999, Americans spent 65 million minutes on “hold” waiting for help from software vendors in debugging software problems (Minasi 2000).