The textbook explanation of the scientific method is “Collect the facts or data. … Formulate a hypothesis. … Plan and do additional experiments to test the hypothesis. … Modify the hypothesis.” And, an experimenter should consider a hypothesis to be a “tentative explanation of certain facts” and must remember that a “well-established hypothesis is called a theory or a model” (Hein and Arena, 2000). This textbook example of the scientific method is correct, but too oversimplified for use in root cause analysis (RCA).