Archive for July, 2013

Poll says no MOE to the current Congress—83 percent disapprove

I just saw this NBC/WSJ poll graphically displayed on the nightly news.  In the small print I saw “MOE +/- 3%” which threw me for a moment wondering if this data was being disrupted by the leader of the Three Stooges.  But then I realized this was the margin of error.  For a helpful detailing of MOE that breaks things down to simpler terms—a giant jar of a 200 million jelly beans—check out this white paper by Roper Center.  Despite the inherent uncertainty of polls (estimated by MOE), the politicians in Washington cannot discount this clarion call (a record percent!) for change.

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“naked statistics” not very revealing

One of my daughters gave me a very readable book by economist Charles Wheelan titled “naked statistics, Stripping the Dread from the Data”.  She knew this would be too simple for me, but figured I might pick up some ways to explain statistics better, which I really appreciate.  However, although I very much liked the way Wheelan keeps things simple and makes it fun, his book never did deliver any nuggets that could be mined for my teachings.  Nevertheless, I do recommend “naked statistics” for anyone who is challenged by this subject.  It helps that author is not a statistician. ; )

By the way, there is very little said in this book about experiment design.  Wheelan mentions in his chapter on “Program Evaluation” the idea of a ‘natural experiment’, that is, a situation where “random circumstances somehow create something approximating a randomized, controlled experiment.”  So far as I am concerned “natural” data (happenstance) and results from an experiment cannot be mixed, thus natural experiment is an oxymoron, but I get the point of exploiting an unusually clean contrast ripe for the picking.  I only advise continued skepticism on any results that come from uncontrolled variables.*

*Wheelan cites this study in which the author, economist Adriana Lleras-Muney, made use of a ‘quasi-natural experiment’ (her term) to conclude that “life expectancy of those adults who reached age thirty-five was extended by an extra one and a half years just by their attending one additional year of school”  (quote from Whelan).  Really!?

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