CAST 2008: Beyond the Boundaries

For years, people have appealed to engineering as the dominant metaphor for how software testing should be done. Yet there are many other metaphors that could provide value to learning about patterns and principles in software testing. As professional testers and nonprofessional musicians, we observe that music affords such a metaphor. What are the parallels between music and testing—especially exploratory approaches to testing? What can we learn from the similarities? In this paper, we explore traditions and contexts; structures of performance in music and testing; ideas associated with tension and resolution; the role of scripting and other artifacts in design, performance, and learning; and skills development. Traditions and Contexts Both testing and music are performed in a wide variety of contexts, with different audiences, different practitioners, and different values for different people. Both fields involve, to a large degree, socially constructed activities, and are suffused with traditions. Living traditions depend on tension between three points of view: a classical aspect, which preserves the foundation of the practice, but which views change and diversity as a threat to the purity of the art; a state of the practice, which advances slowly while absorbing some forms of change and resisting others; and an avant-garde, which stretches the limits and boundaries of the state of the art by bringing in influences from outside and synthesizing new forms, but which may not feel beholden to the classical foundations. The classicists and the avant-garde tend to argue with one another, while the middle ground simply proceeds without paying too much attention to the other extremes. In music, cultures and subcultures abound, crosspollinating one another. For example, Irish traditional dance music, a subculture of Celtic traditions that also include Scottish, Breton, Welsh, Cape Breton, has at least four dominant sub-styles (Clare, Sligo, Donegal, and Cork/Sliabh Luachra). The blues has Chicago, Memphis and Mississippi Delta traditions, as well as boogie woogie, country blues and blues rock. One example of a veritable hotbed of colliding musical styles is Zydeco, a style of music created in Louisiana. Zydeco began as a fusion of Creole, Cajun (from ―Acadian‖—itself a blend of French and Celtic styles from Canada’s east cost) and traditional American music. It has further evolved to include influences from blues, jazz, gospel, and other popular North American music as well as Caribbean influences such as salsa, rumba and calypso, among others. It’s not uncommon to hear hip hop styling or steel drums behind the driving accordion that is a trademark of the genre. It’s important for both testers and musicians to perform in a manner appropriate to the context. Electronic dance music tends not to go over well in a church that favours Gregorian plainchant for its liturgical music. On the other hand, in a supportive context, musical styles can blend, leading to fusion and innovation that can advance new traditions and recall old ones. The startlingly successful Enigma recordings of the early 1990s may have contributed to the success of the fusion of plainsong and chant with dance music during that decade. Testing has been (somewhat controversially) categorized into schools [Pettichord2003]. We assert that these schools can be seen as analogous to musical traditions. Schools of testing can be strengthened by adding techniques and models associated with other schools. In software testing, opponents to the schools categorization often claim that all testing styles are the same, and that division is unnecessary. In music, diversity is embraced and encouraged, and has led to discovery and growth. In testing, we can also profit from identifying different ideas, styles and interpretations. The recognition of specialization and focuses from each of these areas will lead to more discovery, communities of practice, and growth for the whole software testing community. To deny the differences of ideas in testing is akin to saying that music is only ―music‖ and any attempt to identify differing styles, traditions and genres is divisive and problematic.