Experimental Design

``Designing" an experiment simply means planning it so that information will be collected which is relevant to the problem under investigation. All too often data are collected which turn out to be of little or no value in any attempted solution of the problem. The design of an experiment is, then, the complete sequence of steps taken ahead of time to insure that the appropriate data will be obtained in a way which permits an objective analysis leading to valid inferences about the stated problem.