Software engineering has come a long way since 1968, when the term was first used at a NATO conference. And software itself has entered our lives in ways that few had anticipated, even a decade ago. So a firm grounding in software engineering theory and practice is essential for understanding how to build good software and for evaluating the risks and opportunities that software presents in our everyday lives. This text represents the blending of the two current software engineering worlds: that of the practitioner, whose main focus is to build high-quality products that perform useful functions, and that of the researcher, who strives to find ways to improve the quality of products and the productivity of those who build them. Edsgar Dykstra continually reminded us that rigor in research and practice tests our understanding of software engineering and helps us to improve our thinking, our approaches, and ultimately our products.