Testing, in its broadest sense, means ensuring that your visionaries and programmers are creating a helpful product that people will actually use. As the two authors of this installment of Bug Report illustrate, understanding how those users will operate your application is more than an exercise in empathy; it's a simple key to avoiding some real usability meltdowns.

The kind of collaboration that Extreme Programming engenders can benefit both publications and development. Writing, like programming, is a naturally iterative, revisionary process. Dana De Witt Luther shares what she's learned about documenting an Extreme Programming project, using iterative planning meetings and story cards.

Brian Marick argues for using testers at the requirements analysis stage of a project. He says, "While QA is primarily about process, testing—my specialty—is about product. Whatever else a tester might do, she certainly eventually exercises the product with the aim of discovering problems a user might encounter. This essay is about that 'whatever else' the tester does."

A use case is a sequence of actions performed by a system, which combined together produce a result of value to a system user. Use cases describe the "process flows" through a system based on its actual likely use, so the test cases derived from use cases are most useful in uncovering defects in the process flows during real-world use of the system. Here is an example of how a use case is used to derive and prioritize test cases.