Based on the underpowered experimental designs by neuroscientists reported in my previous blog, I am skeptical of these new findings, but they are very intriguing, nonetheless:
- Shocks to the Brain Improve Mathematical Abilities. (You ‘mathaletes’ should do some calculating before wiring up because the sample size for these findings is miniscule!)
- Brain, Interrupted-How distractions make us dumber. (The news here is mixed:Multitasking may be a myth but perhaps some people, with practice, can handle it.)
I hope this blog did not derail your train of thought. If so, go lick a battery to reverse the brain drain.
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
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.
See 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!
George Box passed away this week at 94. Having a rare combination of numerical and communication skills along with an abundance of common sense, this fellow made incredible contributions to the cause of industrial experimenters. For more about George, see this wonderful tribute by John Hunter.
My memorable stories about Box both relate to his way with words that cut directly to a point:
- In 1989 at the Annual Quality Congress in Toronto seeing him open his debate with competing guru Genichi Taguchi by throwing two words on an overhead projector–”Obscurity” and “Profundity”, and then after a dramatic pause, adding the not-equal sign between them. This caused Taguchi’s son Shin to leap up from the front row and defend his father. This cause the largest crowd I have ever seen at a technical conference to produce a collective gasp that one only rarely experiences.
- In 1996 at a DOE workshop in Madison, Wisconsin enjoying his comeback to a very irritating disciple of Taguchi who kept interrupting the lecture: “If you are going to do something, you may as well do it right.”
Lest this give the impression that Box was mean-spirited see this well-reasoned white paper that provides a fair balance of praise and criticism of Taguchi, who created a huge push forward for the cause of planned experimentation for quality improvement.
The body of work by George Box in his field is monumental. It provides the foundation for all that we do at Stat-Ease. Thank you George, may you rest in peace!
Before the first round of NCAA basketball playoffs a number of pundits favored my Minnesota team to upset UCLA—one of the commentators before the broadcast last night went so far as to say they were a “lock”. Now I believe it. (They won.) However, I am doubtful they can beat Florida Sunday—gophers just do not stand a chance against gators. For a more reasoned breakdown on the odds for Sunday and beyond, see this bracket filled out superstar statistician Nate Silver for the New York Times.
People who can crunch data like Silver are in big demand these days according to Wall Street Journal Numbers Guy Carl Bialik in his column on March 2. The jobs site icrunchdata (very descriptive!) posted 28,305 openings for jobs in statistics and the like last month—up from 16,500 openings three years ago (I love data like this!).
It seems that number-herding nerds now rule, but there is a catch according to Dan Thorpe, senior director for analytics at Wal-Mart. He says that “the bulk of the people coming out [with statistics degrees] are technically competent but they’re missing the consultative and the soft skills, everything else they need to be successful.” So, which to do you prefer—good math skills (and lots of money) or an attractive personality (and many friends)? My advice is to aim for some of both.
Check out this graphic by Climate Central. It shows Minnesota being the leader for winter warming from 1970 to 2012! Unfortunately, as usual, we do not do well when at the top and so a great deal of snow fell this winter and more is forecast for next week.
Given the equinox does not come until March 20 at 11:02 GMT, I remain hopeful for Spring. I am invested in warmer weather having bought tickets to opening day for the Minnesota Twins on April 1. Perhaps that was a bit foolish, but at least I will fit in with the theme for this day. Also, I predict that our baseball team will make it to the playoffs. Mark my words.
Winter retains its grip up here in Minnesota at this time of the year, but the days are getting longer and the Twins are in camp down in Florida, so Spring fever is building. I can’t wait to get out to a game at Target Field with the sun shining and our nine flagging down fly balls and bashing them out of the park.
It will be interesting to see if the bloom comes off the rose of our new stadium now that our home team has stunk up the place for two years running. However, Minnesotans are so crazy to get outdoors after being stuck indoors for half the year that they may not care that their club has regressed to its mediocre mean.
According to this article in the latest Chance magazine new stadiums do not make teams statistically more competitive. Yes, teams do increase payroll in conjunction with the greater revenues coming from flocks of fans that come with their new digs. But this drops off in a year or two and things go back to the way they were.
I am not surprised. Nevertheless, I am positive that the Twins will come around this year and make it to the playoffs. That is the nature of a true baseball fan—hopeless optimism.
Inspired by my new web-based “Launch Pad” to the book DOE Simplified, PhD biologist Gaston Habets put his new statistical know-how to good use in his own backyard out in California by offering a choice of beer to the slugs eating up his garden.
Being a native of a cold clime I’d no idea how troublesome slugs could be until some years ago when my cousin in the Bay Area had me out to her place for dinner and asked me to help her gather up greens from the garden. The size of the slugs surprised me: The Pacific banana slug approaches a foot in length according to this New York Times science blog.
Given their gentle nature and top speed of 0.0055 miles per hour, one need not fear these slimy creatures. The only thing is that they eat up the gardens. So that sets the stage for the humane solution of sidetracking slugs with a bowl of beer. But which brew do they prefer? Gaston did his bit for the sake of garden science by setting out eight trays at specific locations around the vegetables and randomly pouring either Bud light or alcohol-free O’Doul’s. He repeated this experiment over four nights in a way that blocked out any differences in the nocturnal feedings.* The graphic shown here shows the outcome: By nearly a 3-to-1 ration slugs preferred Bud Light over the O’Doul’s. They did not get thrown off by the random location of the beer—the slugs found their favorite bars and bellied up.
*Gaston’s data showed a maximum slug count on Saturday night, but then they dropped off to a minimum on Sunday. My conclusion is that slugs party hearty. Who knew?
P.S. It seems that slugs from coast to coast really do prefer Bud from what I see here.
The Scientist reports here that new mathematical studies refute previous findings that most current published medical research findings are false due to small study sizes and bias. I suppose–considering the original assertion of “most” announced discoveries being wrong–we can literally live with a false positive rate of ‘only’ 14% for findings that relate ultimately to our well being. But the best advice is:
It is still important to report estimates and confidence intervals in addition to or instead of p-values when possible so that both statistical and scientific significance can be judged by readers.
- Leah R. Jager, Jeffrey T. Leek (“Empirical estimates suggest most published medical research is true”)