Stats Made Easy

Yesterday I made my weekly Saturday morning trek to our local bank to deposit checks. Yes, I know this is old-fashioned, but I enjoy the exercise, talking with the tellers and keeping my calculating skills sharpened. However, I always warn that my bottom line should not be banked upon –- somehow, despite being an engineer with an MBA, I fall short of being confident at the level required for such endeavors (one hopes one-hundred percent!).

Do not get me wrong: I like calculators. I remember dealing with chemical engineering problems when I was an undergraduate at University of Minnesota. Many could be handled by my K&E slide rule,* but round-off error bothered me, especially for performing anti-logs, which magnify discrepancies. That’s why I might wait an hour or more to use the one Wang calculator provided for use by students in U-of-M’s Institute of Technology. They kept it in a windowless, darkened cubicle where the red numbers glowed all-knowingly to 10 significant digits. Awesome!

Now, of course, calculators have become virtual by way of the personal computer. You will likely find just the one needed for a particular problem at MARTINDALE’S CALCULATORS ON-LINE CENTER. One that I found interesting is the Research Randomizer provided freely by the Social Psychology Network (“SPN”). Although it looks quite easy and appears effective for laying out experiments in random order or choosing samples, the developers of this calculator (Geoffrey C. Urbaniak and Scott Plous) admit that more genuine results are produced via radioactive decay, as can be seen (and heard with annoying effect) at a web site by Fourmilab Switzerland called HotBits.

As you can see from the picture, I am working on taxes today for my two remaining dependents who both earned enough money to buy their own movie tickets and lots of things at the local shopping malls. I wonder… if I enter a few calculation errors in these small fry, will the IRS be distracted from the bigger fish like me? However, I fear they apply a random sampling component to counteract any selection bias. A macabre (but not random) thought arises to end this blog: Which would be worse? Being subjected to a tax audit? Or running the risk of exposure to radioactivity for very brief, but possibly hazardous, time?

*For a fascinating look at the old-fashioned ‘slip stick’, see this web site by the International Slide Rule Museum.