RANDOMIZED VERSUS OBSERVATIONAL STUDIESWHY DO WE NEED A STATISTICAL APPROACH?EXAMPLES OF PROCESS EXPERIMENTSSTATISTICAL APPROACH TO EXPERIMENTATIONTWO-FACTOR EXPERIMENTS: A CASE STUDYTHREE-FACTOR EXPERIMENTS: A CASE STUDYLARGER EXPERIMENTSBLOCKING, RANDOMIZATION, AND CENTER POINTSSUMMARY AND LOOKING FORWARDPROJECT UPDATEEXERCISES: CHAPTER 8NOTES