Experimentation is central to the scientific process. Only experiments test theories. Only experiments can explore critical factors and bring new phenomena to light so theories can be formulated in the first place. Without experiments in the tradition of science, computer science is in danger of drying up and becoming an auxiliary discipline. The current pressure to concentrate on applications is the writing on the wall.
I have no doubt that computer science is a fundamental science of great intellectual depth and importance. Much has already been achieved. Computer technology has changed society, and computer science is in the process of deeply affecting the weltanschauung of the general public. There is also much evidence suggesting that the scientific method applies. As computer science leaves adolescence behind, I hope to see the experimental branch of this discipline flourish.
Acknowledgments This essay has benefited tremendously from numerous discussions with colleagues. I'm especially grateful for thought-provoking comments by Les Hatton, Ernst Heinz, James Hunt, Paul Lukowicz, Anneliese v. Mayrhauser, David Notkin, Shari Lawrence Pfleeger, Adam Porter, Lutz Prechelt, and Larry Votta.