The New York Times Sunday Review features an opinion by Wharton School Professor Adam Grant as to Why We Should Stop Grading Students on a Curve. He asserts that his peers now give over 40% of their grades at A level—a percentage that has grown steadily for the last 30 years as detailed in this March 2016 report by GradeInflation.com. I am not surprised to see my alma mater the University of Minnesota near the top on the chart of Long Term Grade Inflation by Institution, because, after all, we pride ourselves on being nice.
During my years at the “U” most classes were graded on the curve, which Prof. Grant abhors for creating too much competition between students. However, it worked for me. I especially liked this system in my statistical thermodynamics class where my final score of 15 out of 100 came out second highest out of all the students, that is, grade A. Ha ha. This last week President Obama chastised the U.S. press for giving Trump a pass based on grading on the curve. I see no problem with that. ; )
I do grant Grant an A for creativity in coming up with a lifeline for struggling students. He allows them to write down the name of a brighter classmate on one multiple choice question. If this presumably smarter student gets it right, that question earns full credit. My only suggestion is that whomever gets called in the most for providing lifelines should be graded A for being on top of the curve. But then I see nothing wrong with rewarding the best and the brightest.
As I’ve blogged before*, algorithms for engineering and statistical use are near and dear to my heart, but not when they become tools of unscrupulous and naïve manipulators. Thus an essay** published on the first of this month by The Guardian about “How algorithms rule our working lives” gave me some concern. In this case the concern is that employers who rely on mathematically modelled ways of sifting through job applications tend to punish the poor.
“Like gods, these mathematical models are opaque, their workings invisible to all but the highest priests in their domain: mathematicians and computer scientists. Their verdicts, even when wrong or harmful, are beyond dispute or appeal. And they tend to punish the poor and the oppressed in our society, while making the rich richer.”
– Cathy O’Neil
Of course we mustn’t blame algorithms per se, but those who write them and/or put them to wrong use. The University of Oxford advises that mathematicians don’t write evil algorithms. This October 2015 post passes along seven utopian principles for ethical code. Good luck with that!
P.S. A tidbit of trivia that I report in my book RSM Simplified: “algorithm” is an eponym for Al-Khwarizm, a ninth century Persian mathematician who wrote the book on “al-jabr” (i.e., algebra). It may turn out to be the most destructive weapon for oppression ever to emerge from the Middle East.
** Adapted from Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy — a new book on business statistics coming out tomorrow by “Math Babe” Cathy O’Neil.
Just the other day a new term came to light for me—a “bright line” rule. Evidently this is commonplace legal jargon that traces back to at least 1946 according to this language log. It refers to “a clear, simple, and objective standard which can be applied to judge a situation” by this USLegal.com definition.
I came across the term in this statement* on p-values from American Statistical Association (ASA) on statistical significance:
“Practices that reduce data analysis or scientific inference to mechanical ‘bright-line’ rules (such as ‘p < 0.05’) for justifying scientific claims or conclusions can lead to erroneous beliefs and poor decision-making.”
The ASA goes on to say:
“Researchers should bring many contextual factors into play to derive scientific inferences, including the design of the study, the quality of the measurements, the external evidence for the phenomenon under study, and the validity off assumptions that underlie the data analysis.”
It is hard to argue that if the p-value is high, the null will fly, that is, results cannot be deemed statistically significant. However, I’ve never bought into 0.05 being the bright-line rule. It is good to see ASA dulling down this overly simplistic statistical standard.
I can see the value for “bright line rules” in legal processes, a case in point being the requirement for the Miranda warning being given to advise US citizens of their rights when being arrested. However, it is ludicrous to apply such dogmatism to statistics.
*(The American Statistician, v70, #2, May 2016, p131)
Watching Brazilian supermodel Gisele Bundchen sashay across the Olympic stadium in Rio reminded me that, while these fashion plates are really dishy to view, they can be very dippy when it comes to forecasting. Every time one of our local weather gurus says that their models are disagreeing, I wonder why they would ask someone like Gisele. What does she and her like know about meteorology?
There really is a connection of fashion and statistical models—the random walk. However, this movement would be more like that of a drunken man than a fashionably-calculated stroll down the catwalk. For example, see this video by an MIT professor showing 7 willy-nilly paths from a single point.
Anyways, I am wandering all over the place with this blog. Mainly I wanted to draw your attention to the Monte Carlo method for forecasting. I used this for my MBA thesis in 1980, burning up many minutes of very expensive main-frame computer time in the late ‘70s. What got me going on this whole Monte Carlo meander is this article from yesterday’s Wall Street Journal. Check out how the European models did better than the Americans on predicting the path of Hurricane Sandy. Evidently the Euros are on to something as detailed in this Scientific American report at the end of last year’s hurricane season.
I have a random thought for improving the American models—ask Cindy Crawford. She graduated as valedictorian of her high school in Illinois and earned a scholarship for chemical engineering at Northwestern University. Cindy has all the talents to create a convergence of fashion and statistical models. That would be really sweet.
It is a demonstrable fact that dogs know calculus as reported here by The Mathematical Association of America. On the other hand, everyone knows that cats, while obviously intelligent, are too lazy to learn any tricks like all dogs do, at least until they become too old. Therefore, for these two reasons, dogs must be smarter than cats by my reckoning.
But now comes news that felines fathom physics, or at least they naturally grasp the principles of gravity. This conclusion comes from an ingenious experiment on thirty cats done by Japanese researchers. The creatures were found to be inordinately curious about magnetic balls that did not fall out of an overturned metal container. For more details, see this recap by phys.org.
Then to make matters worse for dog lovers like myself, a recent study by a Wisconsin researcher indicates that cat owners are smarter than dog owners. Read it here in Psychology Today and whimper. If it’s any consolation, the study shows that dog people are less neurotic.
“The greatest pleasure of a dog is that you may make a fool of yourself with him, and not only will he not scold you, but he will make a fool of himself, too.”
― Samuel Butler
The controllers of clocks at the International Earth Rotation and Reference Systems Service (IERS) decided recently that 2016 ought to leap an extra second to stay in synch with Earth’s rotation. This will create a great deal of consternation for computers, thus IERS is giving six months’ notice for IT people to prepare themselves. Despite that lead time, about 10 percent of networks around the world are expected to fail, e.g.; a worldwide airline booking system that went down in 2012 for several hours when its computers’ internal clocks could not reconcile the discrepancy with outside systems. (I suggest you stock up on water, food stuffs and toilet paper.)
- Clocks will read 23:59:60 on the 31st of December (I am doubtful this will work on my timepieces)
- 86,400 seconds tick off every day on the master atomic clock for Coordinated Universal Time (UTC), however; the push and pull of the Moon causes the Earths massively heavy oceans to slosh around, which decelerates the spin between 1.5 and two milliseconds every 24 hours, on average.
- Gauging by sightlines from far off galaxies, IERS monitors changes to Earth’s spin. When it goes off by more than 0.9 seconds plus or minus, they mandate a 1 second adjustment.
- In 1972, when the adjustments began, the world got 10 extra seconds to make up for lost time. Since then 16 more seconds have been added—the last one on June 30, 2015. IERS have never removed a second. (If you are a rocket scientist, please compute how long it will it be until the Earth stops and let me know so I have plenty of time to begin packing up my things.)
Since antiquity the Earth’s rotation has provided us with our timescale – it is the Earth’s rotation that gives us our most basic unit of time, the solar day.
— Rory McEvoy, Curator of Horology, Royal Observatory Greenwich
According to this Wall Street Journal report, call-center workers given “stand-capable” desks were 46% more productive than their peers who remained sitting. This astounding improvement in output is attributed to the benefits of moving around.
“We hope this work will show companies that although there might be some costs involved in providing stand-capable workstations, increased employee productivity over time will more than offset these initial expenses.”
-Mark Benden, Director of the Texas A&M Ergonomics Center
P.S. It seems to me from what I gather off the internet that sitting or standing all day at work may not be as healthy as varying positions, e.g., see this essay from 538 blog.
While taking the scenic route back to Munich from Mad King Ludwig’s fairy-tale Neuschwanstein Castle Neuschwanstein Castle, I looked up and saw this flimsy strand several hundred feet overhead just over the Austrian border. My daughter and her husband insisted on hiking up to walk across it. Being a sucker for a dare, I could not resist joining them. (My wife wisely stayed behind.) It was awesome being up so high and swaying in the wind on the 1,322 foot journey each way above the chasm.
The Tibetan-style footbridge is called the Highline179 after the tourist route that winds through this part of the Tyrol. It supposedly can hold up to 500 people. However, I would not like to do a confirmatory test of this specification. By the way, the ruins in the background are Fort Claudia–an outpost of Ehrenberg Castle.
If you are not afraid of heights, check out this video made during construction of Highline179.
Despite odds of only 1 in nearly 300 million for a win, Americans are lining up to buy tickets for a chance at the ninth largest jackpot in U.S. history. Why bother? Evidently most of us, e.g., my wife,* suffer from “availability bias”. This occurs due to the diabolical way that lottery officials publicize winners, which when magnified by the media, makes is seem that these windfalls are commonplace.
Another fallacy, which tricks analytical types like me, is assuming that expected value becomes positive when the jackpot builds. That is, for every $1 invested, more than that is likely to be returned, at least on average. The flaw in this calculation is that lottomaniacs swarm on the big pots, thus making it very likely that the payoff must then be shared among multiple winners. For details, follow this thread on XKCD’s forum.
*I asked her “If you won the lottery, would you still love me?’” and she said: “Of course I would. I’d miss you, but I’d still love you.” (Credit goes Irish comedian Frank Carson for this witty comeback.)
Hey guys, if you want to make more money and live longer, have kids. Anyways that seems to be the gist of two studies reported this month, at least from my perspective as a father of five. Here is the scoop:
- “Men in the top 1 percent distribution level live about 15 years longer than men in the bottom 1 percent on the income distribution in the United States.” – Raj Chetty, professor of economics at Stanford University, quoted in this report by NPR on an article in The Journal of American Medical Association on “The Association Between Income and Life Expectancy in the United States, 2001-2014” he lead-authored.
- Working fathers enjoy 21% ‘wage bonus’ over childless colleagues according to a study by United Kingdom’s Trades Union Congress reported here
Before you run off madly making babies, that correlation may not be causation. For example, as reported in this expose by Slate, statistics indicate that eating ice cream turns people into killers. Could that really be the scoop?