In this morning’s statistics class, when Professor J*#^% asked someone for a value, a student answered with “.4” The response prompted the professor to note that he (and most statisticians) likes values taken to at least three places… .4257 being a much preferred answer to .4.
The incident prompted him to tell us a brief story about precision.
Seems that our professor was in a Differential Equations class way back when. The class was discussing the results of a test when one student protested a 10 point deduction for placing a minus (-) in a section of his answer when none was called for. The (since deceased) professor responded with this:
Son, I was in school with a boy that eventually went on to become a pharmacist. He was pretty good, too. Well, one day, a customer came to him with a prescription, and he set right to work on filling that prescription. He performed the necessary calculations, measured out the correct proportions, and mixed that prescription for the customer. Only thing was, he put a minus (-) in his equation that shouldn’t have been there. The customer took that prescription home and gave it to her baby. The baby died. I took those ten points off your grade because I don’t want you killing any babies.
So, Professor J*#^% and his classmates embraced their professor’s sage advice. From that moment forward, whenever they compared grades, the question became: “How did you do?” and the answer was: “Oh, I killed two babies” or “Killed one baby”, or on a really bad test, “Killed 4 babies”.
Now, whether you, dear reader, are appalled or not, rest assured that every one us in that statistics class knows (forever) the value of precision.