Murray Sidman’s (1960) Tactics of Scientific Research: Evaluating Experimental Data in Psychology just celebrated its sixtieth anniversary. It is without doubt one of the most influential books in the history of Behavior Analysis. This review outlines the rationales for, and details of, methods for the investigation of the behavior of individual subjects that Sidman presented. Many of his observations and recommendations are as timely as ever, maybe even more so, given the “reproducibility crisis” and one of its major origins.