Informal experimentation is as old as humankind. Statisticians became seriously involved in the conduct of experiments during the early 1900s when they devised methods for the design of efficient field trials to improve agricultural yields. During the 1900s statistical methodology was developed for many complicated sampling settings and a wide variety of design objectives.
Santner, Thomas J., "These Aren't Your Mothers and Fathers Experiments (Abstract)" (2009). Kenneth C. Schraut Memorial Lectures. 14.