This article discusses the dark underbelly of derivation: the fragile base class. It's possible to modify a base class in such a way that, even though you've improved its implementation and all your tests work just fine, you've nonetheless damaged the derived classes, perhaps fatally.

Most people don't fully understand the complexities and scope of a software performance test. Too often performance testing is assessed in the same manner as functional testing and, as a result, fails miserably. In this four-part series we will examine what it takes to properly plan, analyze, design, and implement a basic performance test. This is not a discussion of advanced performance techniques or analytical methods; these are the basic problems that must be addressed in software performance testing.

A focused approach toward testing a product is important, but sometimes we discover information that we didn't anticipate at all. One of the key skills in testing is dynamically managing our focus; sharpening it sometimes and widening it at other times. If we vary our approaches, we might find something surprising and broaden our coverage.

The benefits of Web services are becoming widely demonstrated and accepted. However, these benefits are not without their own challenges. How can you enter data and verify the response of a system without a GUI? Are you ready to tame this headless beast?