Abstract
In the Cutter Lecture for 1959 published elsewhere in this issue of the Journal, Dr. Dorn accepts the thesis propounded by A. Bradford Hill from the same forum six years ago1 that the observation of phenomena as they occur in nature is a desirable and often the only possible method of study of causal association, even though experiment offers the most critical method of testing hypotheses. In this year's lecture, Dr. Dorn asks how observations of natural phenomena can be ordered so that they can approach the sharpness of the results of deliberate experiment. He is particularly concerned with the . . .

This publication has 3 references indexed in Scilit: