Archive for category Uncategorized
Models snowed by vagaries of winter weather
Posted by mark in Uncategorized on February 24, 2008
When warned of winter storms, my wife must pay attention because she teaches preschool, which might be canceled if enough snow falls. The weathercasters like to tell us where their models predict the heaviest bands of precipitation, but often these fall all over the map. The TV meteorologists then say the “the models don’t agree” as a hedge against being blamed for a bad forecast. My standard joke to my spouse, who just wants a simple answer on the amount of snow to be expected, is that of course you cannot get models to provide consistent insights on such complicated natural phenomena – they are far too busy primping themselves for their next photographic shoot! (In my mind I always picture at this point the shallow character Ben Stiller played in the movie Zoolander and his inane arguments with fellow models.)
On a more serious note, it came to my attention (a bit belatedly) that the American Statistical Association (ASA) issued a Statement On Climate Change change several months ago. It included this statement: “The design and analysis of computer experiments [DACE] is an area of statistics that is appropriate for aiding the development and use of climate models. Statistically based experimental designs, not currently used in this field, could be more powerful.” I added the acronym DACE as the shorthand for an approach that seems to be getting more-and-more attention as simulations increasingly complex. The objective of DACE is to produce a transfer or surrogate function that provides an adequate approximation of what the simulation actually predicts. Because these computer programs often are very costly to run, a model of its output can be very valuable for taking short cuts to areas of primary interest by researchers. For example, see this DACE done by Canadian hydrologists studying the Smokey-River watershed in the Edmonton, Alberta area.
I also found a website offering Postdoctoral Opportunities in Statistics at the National Center for Atmospheric Research that includes a number of nuggets for further data mining. The abstract for a project on Estimation of Climate Model Parameters, notes that this work is “a novel implementation of new methodology called ‘Design and Analysis of Computer Experiments’ (DACE)” and that “some computer experiments will always be too expensive to run, so one must be judicious in the experiments that are run.”
In any case, I liked all the colored pictures of contour maps, radar images, hurricanes and tornadoes. It looks compelling enough to distract even a real model from their mirror.
Counterintuitive finding: Sugar substitute correlated to weight GAIN
Posted by mark in Uncategorized on February 18, 2008
Purdue University researchers revealed earlier this month that the artificial sweetener saccharin caused rats to put on more weight than others fed sugar. Manufacturers of the sugar substitute responded that this study oversimplified cause for obesity, which involve many factors. See this report by Los Angeles Times Staff Writer Denise Gellene for both sides of the story.
I have no idea if this result will extrapolate to humans, but I would not be shocked if it did. As I gain life experience (that is, get older), my skepticism about generally-held, but never tested, assumptions grow stronger. I find myself more and more reluctant to jump on board with what most people come to accept as irrefutable. Thus a counterintuitive result like this, that something thought to reduce weight actual induces it, does not surprise me.
If you find this result to be difficult to swallow (ha ha), think of how hard it must have been to give up the obvious fact of the earth being flat. Famed physicist Stephen Hawking opens his classic book A Brief History of Time with the story (probably apocryphal) of a flat-earth believer who says to a cosmologist that the earth is supported on the back of a tortoise. When asked how this can be supported, she triumphantly declares that it is turtles all the way down.
“The path of sound credence is through the thick forest of skepticism.”
– George Jean Nathan
Smoker vindicated: Saves $90,000 in health care by not quitting
Posted by mark in Uncategorized on February 9, 2008
In my last blog I mildly mocked a colleague who defended his smoking habit by claiming it would kill him younger and thus save on health care. Dutch researchers recently released a study that supports this non-intuitive repercussion of an unhealthy lifestyle. They calculate the cost of care to be $90,000 less for the tobacco junkies versus those who lead a healthy life. They also threw cold water on the idea that obesity weighs down healthcare systems: By eating as much as they like, the eager eaters save nearly $50,000 in lifetime medical costs. Unfortunately these savings in caring for smokers and obese people come at the cost of shorter life spans. See the study’s stats at this article by Maria Cheng of Associated Press.
This begs the question as to whether it’s worth spending a great deal of money on government programs aimed at prevention of smoking and the like. Some might wonder whether these expenditures make much of a dent in the rates of tobacco addiction. However, a new report issued by the American Journal of Public Health claims that U.S. states that spent more on anti-smoking programs had the fewest smokers. (One wonders if this is correlation or causation.) Furthermore, the Centers for Disease Control and Prevention (CDC), a co-sponsor of the study, say that all but four states devote less than they recommend on the hazards of tobacco use. The CDC calculates that there would be 7 million fewer smokers in the USA had more money been spent. Evidently the state health officials came to their own conclusions on the costs versus benefits of attempting to dissuade smokers from shortening their lives as a desirable tradeoff for the “comfort” ( as the statistician Cochran put it) of their cigarettes.
The smoking statistician
Posted by mark in Uncategorized on February 1, 2008
The other day my daughter Carrie sent me this interesting bit of trivia on the field of statistics:
“Today in English we discussed some stuff that you should put in your blog. We are reading a book about the history of cigarettes.* It is pretty dry, but there are some interesting things. We discussed the first Surgeon General’s panel, which was set up like a jury. Each side (tobacco and anti-tobacco lobbyists) was allowed to eliminate possible panel members as they saw fit. The final panel included a statistician. The man was also a smoker, and after seeing the results of the studies he announced that based on the statistical evidence, despite pleas from his friends and family, the emotional benefits outweighed the health risks.
Here is the relevant passage:
‘In spite of the findings, as well as the urgings of his fellow committee members and the entreaties of his wife and daughter, Cochran relied on his own statistical analysis to support his decision to continue smoking. Having smoked for a long time, he could not become a statistical non-smoker, only a former smoker. Quitting now, he reasoned, would reduce his chances of succumbing to lung cancer from 40 percent higher than a non-smoker’s to 24 percent. ‘I think the comfort of my cigarettes is worth that 16 percent chance,’ he explained. He nonetheless conceded that he would probably cut down, and he noted that, ‘I certainly intend to see that my children never start.’
It sounds like the kind of crazy statistician logic that you would use! Cochran is William Cochran, and the panel was during the Kennedy administration.”
Cochran co-authored a book on Experimental Designs, so I’d heard of him (the American Statistical Association offers this detailed bio). I like this observation of Cochran about response surface methods (RSM): “… polynomials are notoriously untrustworthy when extrapolated.” Before Carrie’s heads-up I remained unaware of Cochran’s connection to the U.S. Public Health Service Advisory Committee formed in 1963 to research the effects of smoking on lung cancer. His cavalier attitude about being addicted to tobacco reminds me of a very sharp programmer who smoked. When hassled about the potential costs in terms of taxpayer-funded health care, his comeback was that smoking kills people at a younger age and thus reduces the ultimate medical expense!
*A Cigarette Century: the Rise, Fall, and Deadly Persistence of the Product that Defined America by Allan M. Brandt.
“THE single most shattering statistic about life in America in the late 1990s was that tobacco killed more people than the combined total of those who died from AIDS, car accidents, alcohol, murder, suicide, illegal drugs and fire.“
— Lead statement from The Economist article An evil weed which features Brandt and his book.
PS.As much as smoking turns me off, I must admit to enjoying Jason Reitman’s movie Thank You for Smoking, which featured an astute lobbyist (played by Aaron Eckhart) who could turn any shot right back at the anti-tobacco forces. It is very amusing to see him skewer the self-righteous Senator (actor William H. Macy).
The real reason why results always vary?
Posted by mark in Uncategorized on January 25, 2008
Many experimenters are plagued by variation. Physicists cite Heisenberg for uncertainty in their measurements. However, most engineers prefer to blame their troubles on the devilish Murphy or elusive gremlins.
Those of us in the computer business swear by, or rather – at, bugs as the culprit for anything that does not go as planned:
“Things were going badly; …Finally, someone located the trouble spot and, using ordinary tweezers, removed the problem, a two-inch moth. From then on, when anything went wrong with a computer, we said it had bugs in it.”
— Admiral Grace Murray Hopper, pioneer computer scientist
PS. The Admiral lived her life at ‘full steam’ as evidenced by this quote : “It’s easier to ask forgiveness than it is to get permission.” (I advise extreme caution if you ever feel compelled to take action on this basis!)
Fun fling with discs in sunny Southern California
Posted by mark in Uncategorized on January 20, 2008
This week sadly marks the demise of Whamo co-founder Richard Knerr – the company who popularized Fred Morrison’s Pluto Platter, re-branded as the “Frisbee.” Plastics were the thing back in those halcyon days of my youth in the 1960’s (the one word advised by the business man in the film The Graduate). However, Whamo’s Hula Hoop failed to ignite my interest, whereas the Frisbee kept me running for hours on end. The older fellows up the hill would float it far down our street for me to happily retrieve.
Throughout my life I’ve kept these plastic discs at hand for impromptu flings. I always brought several along on family camping trips we took throughout Minnesota in the 1980’s. I would designate a tree down the State park’s lane as flag number one and challenge my two boys to hit it before me. When they bonked the bark first, it was the winner’s prerogative to choose the next destination.
Evidently this proved to be a hit with my oldest son Ben, because he became an avid disc golfer. I’ve accompanied him on occasion and been privileged to see Ben make two aces, that is, the first toss going directly into the basket. These typically feature chain link ‘catchers’ that provide a very satisfactory ‘kachink’ when hit straight-on by the flying lid. By dint of keeping my throws short and accurate, I sometimes enjoy this sensational sussuration before my long-tossing offspring, but not often.
The week before last I enjoyed a great buddy trip with Ben doing some disc golfing in Southern California. We stayed with my aunt and her son (my first cousin) at their homes in Corona Del Mar. She found it amusing that grown men would play “Disco” golf, perhaps imagining a Travola-like stroll down the fairway to the tune of the BeeGee’s Stayin’ Alive. For me it was more of a good walk soiled by my ultimately successful attempt at retrieving a disk before if floated away on a muddy pond (pictured above) at Emerald Isle Golf Course outside Oceanside, CA. Ben ran into problems at another disc golf course in La Mirada’s Regional Park. I think it was hole 22 where his ‘driver’ floated over the fence into a back yard guarded two dogs – a little yapper and an ominously silent pit bull. I hope they enjoyed their new toy.
Like the more traditional golfing with balls, one must learn to move on from lost or irretrievable disks and remain mellow. To me, that’s what Frisbee was all about, so it really is an end of an era now that Whamo’s co-founder has passed on — to greener pastures, I hope.
PS. My daughters all enjoy doing the “disko” too. For example, Katie and her cousin did an experiment on a variety of brands and configurations, such as rings, which I documented in a Stat-Teaser article titled Sixth-Graders Experiment with Flying Disks. It generated a surprising number of responses, including:
– Support for the girls’ hypothesis that color might create an effect (an expert on plastics pointed out that pigments vary by weight)*
– A picture sent by University of Nevada Las Vegas Professor D. W. Pepper of a 10-foot wide disc made by an engineering student who purportedly threw it 1000 feet outside Reno, which generated reports of UFOs.** (I would enjoy the look of the La Mirada pit bull seeing this sky-blotting saucer sail over the fence!)
*See item #5 in my October 2002 DOE FAQ Alert
**Details reported in #6 of November 2002 DOE FAQ Alert
“Random” banished by Lake Superior State’s grammar guardians
Posted by mark in Uncategorized on January 3, 2008
“Random” evidently has become synonymous with “unknown” – a frightener for girls describing an encounter with a guy. As the father of three daughters, I admit that this is very scary!
It turns out that I keep a random guy in my office. His name is “Clocky” (see picture). He goes off at proscribed (not random) times, but even though I control this, it always scares me. You see, Clocky was diabolically designed to be most annoying. First he jumps off his shelf. Then he whistles and squeaks while moving at alarming speed in random directions. One day I left work early before Clocky went berserk. This caused quite a commotion at the Stat-Ease office before one of our programmers deciphered the sequence of buttons required to defuse this runaway terminator of peace and quiet.
For the story of the MIT student who invented this clock with a built-in microprocessor that randomly programs its runaway speed and routes, see this article from the Boston Globe . Clocky can be purchased from Think Geek. (I got mine as a gift from my geeky gadget-loving younger brother.) Their web site for Clocky features a video of some random guy wearing a “Toxic Waste” shirt.
Wouldn’t it be nice if alarm clocks could be banished? Making one act randomly is either a stroke of genius or a criminal act – I cannot decide which.
Medical writer’s ’08 resolution: Do not report results from poorly designed experiments
Posted by mark in Uncategorized on December 30, 2007
Earlier this month,* Newsweek’s “Health Matters” columnist Jerry More resolved that
“I will not report on any amazing new treatments for anything, unless they were tested in large, randomized, placebo-controlled, double-blind clinical trials published in high-quality peer-reviewed medical journals.”
He was “shamed” into this by biostatistician R. Barker Bausell’s book Snake Oil Science. Based on observations of his own loved ones, Bausell explains how immensely powerful placebo effects make almost any medical treatment appear to work, even though they are often caused by faith alone. Those who feel the benefits, whether it be placebo or physical (double-blind verified), usually do not care how this comes to pass. However, Bausell makes the case that placebo effects tend to be mild and temporary.
In an ironic twist of Jerry More’s resolution, Bausell advises that those afflicted with chronic health problems seek a promising remedy from an enthusiastic promoter and take the plunge with no reservations, thus maximizing any placebo effect!
Obviously one must be extremely cautious about side effects from any such purported therapy or substance. For example, some years ago my wife and I hosted a weight-obsessed exchange 16-year-old student from Mexico who harbored strong faith in alternative medicines (an oxymoron?) for curbing appetite. One day while shopping at a local mall, she got away from me and made a bee line to a health-food store. I found her at the counter with half a dozen bottles of very potent natural (?) substances that the teenage clerk recommended to her. I hustled us out of there without making that purchase.
Blind faith just does not work well for me. I like the double-blind approach much better.
Tidings and tools for Yule
Posted by mark in Uncategorized on December 24, 2007
Sports ‘randomination’?
Posted by mark in Uncategorized on December 16, 2007

It turns out that I performed an experiment back in my days as a slow-pitch softball player. At that time my position was ‘rover’ – a tenth man who augmented the normal three who play the outfield in baseball. Depending on my whim, I would play ‘long’ – I line with the other outfielders – or ‘short’ – nearer the infield in a gap where I guessed a batter might want to drop a hit. It occurred to me that by randomly positioning myself inning-by-inning from one game to the next and measuring the oppositions success I might develop statistics that would show favor to either short or long as a general practice. Our team was originally sponsored by General Mills Chemical Technical Center, so my mates met this proposal with surprising enthusiasm. After all, our prospects for winning in our Class D (lowest level) league were never very good.
As Yogi Berra said, “We were overwhelming underdogs.”
One thing we could count on is that during any given inning, the opposition would be sure to achieve some hits, if not runs. However, it seemed likely that while playing short might cut off singles, it would lead to more doubles and triples from players knocking the softball over my head. Therefore my teammates and I agreed that total bases would be a good measure of success. Thus we counted a single as one, a double as two and so forth. (If you are not familiar with the game of baseball, see these simplified baseball rules from Wikipedia). Since opponents varied in their quality of play, I laid out a randomized block experiment game-by-game (results in first graph — the points labeled “2” represent two innings with the same total bases).