Archive for category Uncategorized
A strange pink elephant — the Higgs boson
Posted by hank in science, Uncategorized on July 9, 2012
In our business we focus a lot of energy to convince experimenters they must conduct enough runs to develop the statistical power needed for detecting an effect of interest. What amazed me about the recent discovery of the Higgs boson is the sample size required to see this “strange pink elephant” as it’s described in the embedded explanatory video cartoon. The boffins of CERN took 40 million measurements per second for 20 years. These physics fellows cannot be topped for being persistent, tenacious, dogged and determined. Good for them and, I suppose, us.
“If the particle doesn’t exist, one in 3.5 million is the chance an experiment like the one announced would nevertheless come up with a result appearing to confirm it does exist.”
– Carl Bialik, ‘The Numbers Guy’ for Wall Street Journal explaining in his July 7-8 column the statistical meaning of CERN’s 5 sigma standard of certainty (see How to Be Sure You’ve Found a Higgs Boson).
Statisticians apply stylometry to identify authors and they invent algorithms that assess essays
Posted by mark in pop, Uncategorized on June 20, 2012
My colleague Tryg, who, like me, loves word play, drew my attention to this podcast* that explains how “By Their Words You Shall Know Them.” I teed it up on my smart phone and listened on my way to work yesterday—a fun way to pass my half hour commute into Minneapolis from my home in Stillwater, Minnesota. One thing that caught my ear was the early 1960s work by Harvard statistician Frederick Mosteller to pin down who wrote 12 of the 85 Federalist papers published under the pen name “Publius”. He and colleague David Wallace (University of Chicago) applied Bayes; theorem to attribute these writings to James Madison (as opposed to Alexander Hamilton). Mosteller also led the way to today’s reliance on statistics in sports by doing the first known academic analysis of baseball in 1946—concluding that luck rules even in a seven game World Series. He didn’t agree that, though the Cardinals beat his home town Red Sox, the best team actually won.
This analytical dissection of written words has come to be known as “stylometry”. As computing power increases and algorithms develop, writings are being put to the test. For example, see this New York Times Digital Domain column from earlier this month that details developments in ‘essay-scoring engines’. For now the students hold the upper hand on computer-based grading of papers—web-based essay mills can easily throw together fact-laden gibberish that fools the virtual professors. These are easily seen by teachers when they skim the results—check out some goofy passages passed along by Duke University professor Dan Ariely in this editorial for the Los Angeles Times .
The advent of spell-checking and grammar inspection in word processors has been a boon for writers. However, passing these tests does not necessarily lead to clear prose. When I started work as an engineer, the head of our process development group handed me a little booklet by Robert Gunning on “How to Take the Fog Out of Writing”. He advocated short, active sentences—not the passive, long and pedantic style I’d grown accustomed to from academia. See how your writing scores for fog using this online tool by Simon Bond. The quote below scored 20.86. This paragraph came back with a fog index of 9.152 (up to this clause to be precise!). Gunning’s score estimates the years of formal education needed to understand text on a first reading. Thus my writing supposedly can be understood by 10th grader. Draw your own conclusions on the readability of our founding fathers.
“As there is a degree of depravity in mankind which requires a certain degree of circumspection and distrust, so there are other qualities in human nature which justify a certain portion of esteem and confidence.”
– Madison, Federalist Papers #55, 346
*By online Slate magazine’s Lexicon Valley host Mike Vuolo
Irish Times says “serious issue settled” — Guinness does indeed travel badly
Posted by mark in Consumer behavior, Uncategorized on June 9, 2012
Lab Times author Thirsty O’Leary provides this summary of a scientific study by Liam Glynn, et al, that proves Guinness beer does not travel well. Some say it’s a conspiracy of the Irish—them drawing off the cream from the barrel. Although Guinness is not my cup of tea, I admire the work that went into this experiment. These zealots for zymurgy went all out! And, as those of use students ; ) of stats know, Guinness goes down well with quantitative research of this sort.*
“Each pint is like a child. You have to mind it through the entire process.”
— Fergal Murray, Guinness brew master
*See Guinnessometrics: Saving Science and Statistics With Beer
Brain drizzling? Try linking instead.
Posted by mark in science, Uncategorized on May 13, 2012
Early on in my career as a chemical engineer working in R&D process development I came to the realization that many good ideas get shot down prematurely. Granted, many of these thoughts come out half baked, but in the proper environment they can lead to some very nourishing developments.
I always thought Osborn’s methods for brainstorming counteracted the quenching of creativity. However, although his approach certainly does generate a quantity of ideas, the end results never proved nearly as astounding as one might expect.
Earlier this year The New Yorker magazine debunked as Groupthink many of Osborn’s cherished tenets, such as allowing no criticism. The current thinking is that you gather a diverse group of bright people and then just let things fly with no holds barred. The fear of public humiliation forces the participants to think a bit before speaking. If they do get strong criticism, these creative people must regroup their thoughts and try again. The best idea(s) tend to win out.
Here is one minor variation on the “no rules” creativity session that I suggest: Ask that everyone come in with one idea to throw into the pot. Then let the fun begin!
Given Osborn’s rules are passé, where should you turn to next for catalyzing creativity? I recommend you consider Idea-Links. I have had the pleasure of picking the brain of the author, Jim Link—a very energizing fellow. Believe me, he really knows how to get people to think outside of the box.
“To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science.”
– Albert Einstein
If you have other ideas on fostering creativity (or wish to criticize those already proposed), toss them into the ring. Do not be shy (nor sensitive).
Beware of obvious answers and positive results
Posted by mark in science, Uncategorized on March 4, 2012
“Most results, including those that appear in top-flight peer-reviewed journals, can’t be reproduced.”
This is a “dirty secret” revealed by the Wall Street Journal’s Gautam Naik in this December report. It cites statistics from Bayer that nearly two-thirds of published studies could not be replicated. Naik blames the complicated nature of experiments nowadays along with the “positive bias” researchers driven to produce results. Glenn Begley, vice president of research at Amgen, a biotechnology company, suggests that “academic scientists, like drug companies, should perform more experiments in a ‘blinded” manner to reduce any bias toward positive findings.”
Meanwhile, Duncan Watts, author of Everything is Obvious: *Once You Know the Answer says
“When you do the experiment properly [randomized and controlled], all the numbers go down.”
He’s speaking on the bias of marketing executives toward their own sensibilities, which often do not reflect those of the population being sold to. See what the Financial Times “undercover economist” Tim Harford says about this here. Unfortunately, in my experience, those (the analysts) who know better than to extrapolate from small, non-representative sample of opinions from the ‘powers-that-be’ (often n=1, that is—the Boss) get very little support for spending money to put these assertions to the test. Even though you know the top dogs might be barking up the wrong tree it’s easiest just to go along with the pack and press ahead. To do otherwise risks suffering a painful bite-back. Yes, I am a cynic.
A debatable question: Should healthy people take cholesterol drugs?
Posted by mark in Uncategorized, Wellness on January 23, 2012
At my annual physical before my heart attack in December of 2004 I was advised that, although the cholesterol came in a bit high, it would not be necessary to go on medicine to reduce this. Would I have been spared if I had? This sort of speculation really does nothing for me but it underscores a big question that is debated in today’s Wall Street Journal: Should Healthy People Take Cholesterol Drugs to Prevent Heart Disease.
You be the judge whether the answer is yes or no—it is far too problematic for me to say. However, here are two points I want to make on the WSJ debate:
“we need clinical trials that actually follow healthy people treated with statins for the long term to see if treatment really results in lower mortality.”
I remain very skeptical of “experiments” comprised in a metamorphic manner by happenstance, as opposed to being truly controlled from start to finish and done double-blind (if possible).
Wrong more often than right but never in doubt
Posted by mark in Consumer behavior, Uncategorized on October 23, 2011
The New York Times Magazine provided a great readout on the “Surety of Fools”* in today’s issue. The author, psychologist Daniel Kahneman, starts by providing a real-life example of WYSIATI – “What you see is all there is.” Read his story to learn more about this, but basically it means that many times what you observe does not provide any meaningful information for predicting future behavior. Cocky Wall Street brokers are hit very hard, especially the males, who “act on their useless ideas significantly more often than women.” Ouch!
Kahneman examined the illusion of skill in a group of investment advisors who competed for annual performance bonuses. He found zero correlation on year-to-year rankings, thus the firm was simply rewarding luck. What I find most interesting is his observation that even when confronted with irrefutable evidence of misplaced confidence in one’s own ability to prognosticate, most people just carry on with the same level of self-assurance.
The bottom line is that you shouldn’t swallow everything said by assertive and confident people who advise on highly-variable systems such as financial markets. Heeding what an experienced physician suggests is one thing, but going with the most boastful money manager is another.
“True intuitive expertise is learned from prolonged experience with good feedback on mistakes.”
— Daniel Kahneman
“It’s what you learn after you know it all that counts.”
— John Wooden
* Posted earlier under a different title here.
Trouble with math & stats? Blame it on dyscalculia.
Posted by mark in Basic stats & math, Uncategorized on October 16, 2011
According to this article in Journal of Child Neurology “dyscalculia is a specific learning disability affecting the normal acquisition of arithmetic skills, which may stem from a brain-based disorder. Are people born with this inability to do math in particular, but otherwise mentally capable – for example in reading and writing? Up until now it’s been difficult to measure. For example, my wife, who has taught preschool for several decades, observes that some of her children progress much more slowly than other. However, she sees no differential in math versus reading – these attributes seem to be completely correlated. The true picture may finally emerge now that Michèle M. M. Mazzocco et al published this paper on how Preschoolers’ Precision of the Approximate Number System Predicts Later School Mathematics Performance.
Certainly many great minds, particularly authors, abhor math and stats, even though they many not suffer from dyscalculia (only numerophobia). The renowned essayist Hillaire Belloc said*
Statistics are the triumph of the quantitative method, and the quantitative method is the victory of sterility and death.
I wonder how he liked balancing his checkbook.
Meanwhile, public figures such as television newscasters and politicians, who appear to be intelligent otherwise (debatable!) say the silliest things when it comes to math and stats. For example a U.S. governor, speaking on his state’s pension fund said that “when they were set up, life expectancy was only 58, so hardly anyone lived long enough to get any money.”** One finds this figure of 58, the life expectancy of men in 1930 when Social Security began, cited often by pundits discussing the problems of retirement funds. Of course this was the life expectancy at birth, in times when infant mortality remained a much higher levels than today. According to this fact sheet by the Social Security Administration (SSA), 6.7 million Americans were aged 65 or older in 1930. This number exhibits an alarming increase. The SSA also provides interesting statistics on Average Remaining Life Expectancy for Those Surviving to Age 65, which show surprisingly slow gains over the decades. I leave it to those of you who are not numerophobic (nor a sufferer of dyscalculia) to reconcile these seemingly contradictory statistical tables.
*From “On Statistics”, The Silence of the Sea, Glendalough Press, 2008 (originally published 1941).
**From “Real world Economics / Errors in economics coverage spread misunderstandings” by Edward Lotterman.
Proofing Blackbeard’s rum
Posted by mark in pop, Uncategorized on September 11, 2011
Being only about a week from this year’s Talk Like a Pirate Day this Atlantic Monthly article (read belatedly from a backlog of magazines) about Gunpowder on the Rocks caught my eye. I like the idea of setting a drink on fire and then drinking it, as Blackbeard did to impress his pirate crew.
It turns out that this is a practical test of rum to ensure it hasn’t been watered down by a ne’er-do-well hornswoggler, as you can see in this video by experimental archaeologist Jeff Lindow. After watching this, I decided not to try this at home as it would no doubt shiver my timbers. However, if it gets cold enough this winter, I might consider a swig of this gunpowder-infused Man O’War rum. Yo ho ho!
It may pay to make your product less than perfect!
Posted by mark in Consumer behavior, Uncategorized on September 4, 2011
I once analyzed data from a designed experiment that quantified consumer distaste for flaws in chocolate-covered cherries. This was a very rewarding project – lots of free candy! It also produced a counter-intuitive result: People preferred boxes with a few upside-down morsels. I figure this is akin to a beauty mark adding to the enticement of a model or actor. This article on “When Blemishing Leads to Blossoming”, published online by the Journal of Consumer Research confirms that under specific circumstances, a flaw makes a product more attractive. For example, in one experiment (highlighted in the July 16 issue of Wall Street Journal) the researchers (Danit Ein-Gar, Baba Shiv, Zakary L. Tormala) offered either perfect or slightly flawed chocolate bars to several hundred relaxed (strolling around) or stressed (rushing to exams) college students. I searched out the results and reproduced them in this interaction graph from Design-Expert® software. It seems to me that this surprising effect, presuming it’s real, provides yet another devious opportunity for marketing mavens to make us buy stuff. One thing I might advise is that you never buy anything when you are in a hurry.
