Smooth sliding for 2011
Posted by mark in Uncategorized on January 1, 2011
Here’s hoping you enjoy smooth sliding in 2011 like I did recently outside my front door.
Happy New Year!
– Mark
PS. Kudos for my daughter Emily for this production.
A fruit fly by any other name is still a fruit fly
A good example of what South Korean educational system produces (see my previous blog) is their first astronaut, bioengineer Yi So-yeon, who was featured in this article Tuesday by The Korea Herald . During her mission at the International Space Station she completed a number of experiments, including one that involved the assistance of 1000 fruit flies.
If I were an astronaut going up with so many flies, I’d shake the container just before lift-off to get them up in the air and lighten the load. I heard about this trick from my next-door neighbor – a bee-keeper. He loaded up too many hives in his truck and it went over-weight, but he beat the inspectors by banging on the side with a hammer as he drove onto the scale.
Having segued to bees, here’s a heads-up about a study done by a group of 8- to 10-year-old British school children from Blackawton Primary School. They trained a bunch of bees to go to specific-colored and/or patterned targets by selectively rewarding them with sugar. This experiment met the standards of the Royal Society, which published the results in this Biology Letter. Also see these kind comments. Wired Science provides a ‘dumbed-down’ version with photos, that is, an executive summary 😉 here.
“We discovered that bumble-bees can use a combination of colour and spatial relationships in deciding which colour of flower to forage from. We also discovered that science is cool and fun because you get to do stuff that no one has ever done before.”
– Children from Blackawton
PS. Some folks think that drosophila melanogaster is a misnomer for this little critter that mysteriously spring up from discarded apples and the like. “The fruit fly’s name is likely to change to Sophophora melanogaster if results of a new evolutionary analysis are accepted” according to this April 2010 bulletin from the International Commission on Zoological Nomenclature. Who made them lords of the fruit fly?
South Korea achieves top ranking for education
Posted by mark in Basic stats & math on December 21, 2010
Based on testing of nearly half a million 15-year-old students worldwide, South Korea ranks as the number 1 country overall for education. It’s laid out beautifully in the graphical illustration by Paul Scruton for this article by UK’s Guardian on which country does best at reading, science and maths. This breaking news is timely for me because I will be in Seoul Thursday giving a presentation hosted by the Department of Statistics at Chung-Ang University. The USA fell far down the list in math, so I suppose I am a bit out of line trying to explain new tools of design of experiments to anyone in this country. ; )
I spoke today to a resident of Busan with a daughter in high school. She said the school runs from 8 in the morning to 8 at night Monday through Friday and a half day every other Saturday. No wonder South Korean teenagers test so highly relative to the USA!
Happy holidays!
The recent collapse of our Hubert H. Hump-free (ha ha) Metrodome makes it seem like we Minnesotans must be completely deflated (pun intended) from the extraordinary snowfall this month. However, there is an upside to this weather – excellent cross-country skiing conditions. As you can see, this has brightened up my disposition. I like nothing better than a ski through the woods near my home in Stillwater, where I often find myself all alone except for a startled deer — I almost literally ran across a doe (the female ungulate, not a design-of-experiment ) yesterday, for example.
Being in good spirits myself, I wish the same for you this holiday season. Enjoy!
“He gives his harness bells a shake
To ask if there is some mistake.
The only other sound’s the sweep
Of easy wind and downy flake.
The woods are lovely, dark and deep.
But I have promises to keep,
And miles to go before I sleep.
And miles to go before I sleep.”
– Excerpt from “Stopping By Woods on a Snowy Evening” by Robert Frost
PS. The shot from ground-level provides the perspective of one of our indigenous snow fleas, which I often see in late winter when it warms up a bit. It’s fun to watch them jump around at random.
Fishing for giant snakes with a boy as bait
Posted by mark in Uncategorized on November 28, 2010
The statistics are:
- Prey: Length 26 feet, weight 320 pounds
- Predator: Length 4 feet (?), weight 90 pounds.
Here in Minnesota we love to tell fishing stories that can be real whoppers, but this one told by Everglades Outpost founder Bob Freer beats all. I heard the story yestesterday on National Public Radio’s “Wait Wait… Don’t Tell Me” show.* Freer and his crew were confounded by a very large snake lurking under a house – the hole would not admit a full-grown adult. Luckily a kid watching the proceedings stepped up to help. The snake hunters tied a rope to his leg and handed him a stick with a napkin tied to it. With the 90-pound boy (brave or foolhardy?) as bait, they fished out a 26-foot long, 320 pound reptile – a python, I presume.**
“We told him to make sure not to tell his mother.”
– Bob Freer
PS. Pictured here in my hand is a Ball python – a popular pet due to being so small (several feet in length and a few pounds at most) in addition to their endearing eponymous tendency to curl up into a comfortable coil.
* See the transcript of “Animal Expert Bob Freer Plays Not My Job” here
** The National Park Service just released their latest statistics on the proliferation of Burmese pythons in the Everglades – see the year-by-year count here.
Prof applies stats to flush out widespread cheating
Posted by mark in Uncategorized on November 24, 2010
See this recent ABC News report on how perhaps as many as 200 University of Central Florida (UCF) students cheated on an exam. The YouTube video of them being accused by the teacher, armed with supporting statistical detail and an actual confession, can be seen here.
“This is what’s called a bimodial distribution… [which].. exists when an external force has been applied… that creates a systematic bias.”
– Professor Richard Quinn describing a histogram of scores from his mid-term test for University of Central Florida Strategic Management 4720
For some alarming stats on percent of students cheating (mostly reported to be well over half!), see this summary of surveys on exam-beaters compiled by a test-security firm (but consider the probability of them being a bit biased!).
Getting back to Professor Quinn, I am amazed at how many commentors blame him for not updating his exams. Evidently students cannot be held accountable for cheating when it is so easy to accomplish. 🙁
“This is college. Everyone cheats, everyone cheats in life in general.”
– CSU student Konstantin Ravvin
Pigging out in Italy – a 30-meter pork roast
Posted by mark in Uncategorized, Wellness on November 21, 2010
We are gathering quantities of food for a Thanksgiving feast at the Anderson home this Thursday. As my stomach rumbles* in anticipation, my thoughts turn to another great feast that I saw prepared last summer in Bergamo, Italy.** There they prepared pork (or porchetta, as they say), rather than the turkey we prefer in the New World. What made this Bergamo barbecue so singular was the way the cooked their pigs – sewn together into a 30 meter roast! See the results in this video I took (produced by my daughter Emily).
A meter or two of this porchetta would be the perfect warm up for our Thanksgiving banquet. I wonder what these Italians would do to dress up a turkey. They sure know how to create a spectacle!
*In medical terms known as “borborygmi” – a normal symptom of hunger.
**See this report
Election day pits pollsters as well as politicians
Posted by mark in politics, Uncategorized on November 2, 2010
Sunday’s St. Paul Pioneer Press reported* an astounding range of predictions for today’s election results for Governor of Minnesota. The Humphrey Institute showed Democrat Dayton leading Republican Emmer by 41 to 29 percent, whereas Survey USA (SUSA) respondents favored Dayton by only 1 percent – 39-38! The SUSA survey included cell-phone-only (CPO) voters for the first time – one of many factors distinguishing it from their competitor for predicting the gubernatorial race.
What I always look for along with such predictions is the margin of error (MOE). The Humphrey Institute pollsters provide these essential statistical details: “751 likely voters living in Minnesota were interviewed by telephone. The margin of error ranges between +/-3.6 percentage points based on the conventional calculation and +/-5.5 percentage points, which is a more cautious estimate that takes into account design effects, in accordance with professional best practices.”** Note that the more conservative MOE (5.5%) still left Dayton with a significant lead, but just barely at 12 points (vs 5.5%x2 = 11% overlap of MOEs).
Survey USA, on the other hand, states their MOE as +/- 4%. They provide a very helpful statistical breakdown by CPO versus landline, gender, age, race, etc. at this web posting. They even include a ‘cross-tab’ on Tea Party Movement – a wild card in this year’s election.
By tomorrow we will see which polls get things right. Also watching results with keen interest will be the consultants who advise politicians on how to bias voters their way. Sunday’s New York Times offered a somewhat cynical report on how these wonks “Nudge the Vote”. For example, political consultant Hal Malchow developed a mailer that listed each recipient’s voting history (whether they bothered to do so, or not), along with their neighborhood (as a whole, I presume). Evidently this created a potent peer pressure that proved to be 10 times more effective in turning non-voters into voters! However, these non-intuitive approaches stem from randomized experiments, which require a control group who get no contacts (Could I volunteer to be in this group?). This creates a conundrum for political activists – they must forego trying to influence these potential voters as the price paid for unbiased results!
“It’s the pollsters that decide. Well, a poll can be skewered [sic #]. I can go out and get you a poll on anything you want and probably get the results that I want just in how I conduct it.”
— Jesse Ventura, professional wrestler (“The Body”) and former governor of Minnesota
# Evidently a Freudian slip – him being skewered on occasion by biased polls. 😉
* “Poll parsing” column by David Brauer, page 15B.
Brain-bending thoughts on a coffee experiment
Posted by mark in design of experiments, Uncategorized, Wellness on October 24, 2010
The Stat-Ease training center here at our world headquarters in Minneapolis features a wonderful single-cup brewing system that you can see demoed here. When we are not holding a workshop, I sometimes sneak in to steal a cup late in the day. By then I am reaching my limit, so I brew a “half-calf” at the half-cup setting. Being a chemical engineer, I calculate that, in this case, half of half makes a whole, that is, coffee with the normal concentration of caffeine. Does that make sense?
Making a tasty and effective cup of coffee is a huge deal for knowledge workers who need to keep their heads in gear from start to finish of every single day. One of our workshop students, a PhD, has been picking my brain about testing coffee blends on her staff of scientists. She proposes to do a mixture design such as I did on varying types of beers (see Mixture Design Brews Up New Beer Cocktail—Black & Blue Moon).
Obviously overall liking on a sensory basis should be first and foremost for such an experiment on coffee – a 5 to 9-point scale works well for this.* However, the tricky part is assessing the impact of coffee for accelerating information processing and general problem-solving, which I hypothesize depends on level of caffeine. I wonder if an online “brain training” service, such as this one developed by neuroscientists at Stanford and UCSF, might provide a valid measure.
The down side of doing a proper test on whether coffee improves cognitive skills will be the necessity of reverting to the base line, that is, every morning getting up and trying to function without the first cup.
“A mathematician is a machine for turning coffee into theorems.”
— Alfréd Rényi
*Turn your volume down (to not hear the advert) and see this primer on sensory evaluation by S-Cool– a UK educational site for teenagers.
Caltech prof puts finger on what turns on consumers
Posted by mark in Consumer behavior on October 20, 2010
The November/December issue of American Scientist provides an intriguing heads-up from Caltech neuroeconomist Antonio Rangel on impulse buying. His group randomly presented items to students in varying ways – by name, picture and with the actual object. Buyers paid 50 percent more for the real goods! However, when the item could be seen under glass but not available to be held, this difference in desirability disappeared. Expect to see even more irresistible items showing up at the checkout counters to entice you into an impulse purchase. : (
“Next time you’re stuffed and the waiter wheels around the dessert cart, know that the odds are against you. Just cross your fingers that the chocolate cakes under a glass dome, to help you resist the urge.”
– Christopher Intagliata, Scientific American reporter (from text of podcast here)
PS. While researching Rangel, I came across this article in the Caltech News on another study he did on buying behavior – in this case the propensity to confuse price with quality for wine. Here you can learn why Rangel is a “neuro” economist – he directly measures brain activity, which provides more reliable measures of consumer response than what they might admit when asked how they feel about something. See how MRI signals change in student brains confronted with money, trinkets versus snacks (can you guess which turns them on the most?) at this web-page detailing research by the Rangel Neuroeconomics Laboratory.