Practical Data Analysis with JMP®

Study Design: Experimentation, Observation, Surveying

If the goal of a study is to demonstrate a cause-and-effect relationship, then the ideal approach is a designed experiment. The hallmark feature of an experiment is that the investigator controls and manipulates the values of one or more variables and then observes changes in the response variable. For example, in the concrete industry engineers might want to know how varying the amount of different additives affects the strength of the concrete. A research team would plan an experiment in which they would systematically vary specific additives and conditions, and then measure the strength of the resulting batch of concrete.

Similarly, consider a large retail company that has a "customer ...