Amazingly, Jan U. Wari has been invited to be a guest lecturer at her local community college. Professor Stan Deviation, her mentor, has nearly given up on the possibility that Wari will become a competent statistician, but knowing that the best way to learn something is to teach it, he recommends Wari for the position, which involves a lecture instructing students about statistics and problem solving.
Wari, who fails in her attempts to secure the title of “Professor,” nonetheless forges ahead with plans for her first lesson. Of course, she has to take several days off from her position at Greer Grate & Gate, since class preparation is so demanding. She decides that she will begin with basic data analysis, to warm up her students and let them experience her own wisdom firsthand.
“Three ways of looking at data are through the concepts of central location, shape, and variability,” she drones. Several students seem to be intent on the content of her lecture, recording her every word on their PDAs. Occasionally their serious concentration seems to be punctuated by beeps and trills, but Wari assumes that the noises are generated by overloading their systems with formulas.
Emboldened, Wari moves next to the concept of control charts, leading the class through an exercise on creating X-bar and R charts, when a student raises her hand to ask a question—always a dangerous moment for Wari, who only skates on the surface of understanding these concepts herself. The student asks about Ishikawa diagrams, which she has noticed are used by colleagues in her part-time job at a local hospital.
Since Wari has never heard of Ishikawa diagrams, she has no idea what she’s talking about. Never at a loss, however, she recovers her composure by defining the Taguchi loss function, since that’s the only statistical concept she knows with a Japanese name and s he assumes they must be related. So she defines Ishikawa diagrams for the student: “That’s a complex statistical methodology used to measure costs when you’re off target,” she says confidently. (Wari is known for her confident attitude.)
Is Wari herself off target? Or did she happen to accidentally score a bull’s eye in her definition?
a) Amazingly, she has managed to identify the Ishikawa diagram without ever seeing one.
b) Sorry, Wari. The only thing Taguchi and Ishikawa have in common is that they’re both named after Japanese statisticians.
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2008 PQ Systems.
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