Archive for April, 2013

Brain scientists flunk statistical standards for power

Last week The Scientist reported that “Bad Stats Plague Neuroscience”.  According to researchers who dissected 730 studies published in 2011, neuroscientists pressed ahead with findings on the basis of only 8 percent median statistical power.  This falls woefully short of the 80 percent power that statistician advise for experimental work.  It seems that the pressure to publish overwhelms the need to run enough tests for detecting important effects.

“In many cases, we’re more incentivized to be productive than to be right.”

–          Marcus Munafo, University of Bristol, UK

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Educational system turned upside down by distance-based learning

I’ve been watching with interest the trend for ‘flipping’ classrooms; that is, using time together for working on homework and leaving the teaching to web-based and other materials (books, still!) for students to teach themselves on their own time.  At the college level this new educational approach for is gaining momentum via massive open online courses, called MOOCS.

For example University of Minnesota chemistry professor Chris Cramer will teach this 9-week MOOC on Statistical Molecular Thermodynamics starting next month.  Follow the link and watch him demonstrate a thermite reaction.  If anyone can make statistical molecular thermodynamics interesting, it will be him, I think, so I enrolled.  It’s free, thus there’s nothing to lose.  Also, I still feel guilty about getting an A grade in the stat thermo class I took 30 years ago—the reason being it was graded on a curve and thus my abysmal final score of 15 out of 100 got rated highly as the second highest in my class.  As you can infer, it was not taught very well!

P.S. I recently unveiled a distance-based lecture series on design of experiments called the DOE Launch Pad.  It augments my book (co-authored by Pat Whitcomb) on DOE Simplified.  Contact me at mark @ statease .com to sign up.  It’s free for now while in pilot stage.

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Statistics provide a decisive advantage to taking one route to work versus another

Spring 2013 driving 35 vs 694 through N St PaulSee the results graphed on an experiment I just completed to decide whether to commute straight in to Minneapolis on Minnesota Highway 36 or take US Interstate 694 –a speedier, but longer, freeway bypass.  Notice that the least significant difference bars do not overlap,  thus providing more than 95 percent confidence that the scales tilt to one way (36) being faster–to put it simply.

For each run into work I randomly chose one route or the other based on a recipe sheet produced by Design-Expert software and timed it with a stopwatch app on my smart phone.     Then I entered the results in the software and it gave me the answer I wanted.

It appears that I can save the better part of a minute by not shooting around on 694.  That is good to know!