U of M News Wire: March 15, 2007

 
 
Statistically speaking, they are ahead of the curve

By Deane Morrison
U of M News Wire
 
As the class begins, the University of Minnesota students debate what "Let's Make a Deal" contestants should do if they've just chosen door number three and host Monty Hall shows them that a booby prize was behind door number two. Do the odds favor a switch to door number one or staying with number three?
 
They could ask Joan Garfield, their statistics professor, but she won't tell. Instead, she has the students play the game in class until the numbers make the answer clear. By having students learn statistics by doing it, Garfield, a professor of educational psychology in the U of M’s College of Education and Human Development, and her colleagues have earned rave reviews from students and a national award for teaching innovation from the American Psychological Association.
 
Presented to the department in February, the Innovative Practices in Graduate Education in Psychology Award was in large part due to Garfield, who was instrumental in reshaping her department's statistics teaching philosophy and style nearly a decade ago. Along with receiving the award, Garfield is also a principal investigator on two grants from the National Science Foundation, one to assess students' statistical reasoning and another to develop class activities and lesson plans.
 
"I think of myself as a revolutionary, trying to overthrow traditional ways of teaching statistics," she says. "I've been given a lot of freedom to do that in educational psychology." Garfield developed a new way to teach the subject and trains graduate students to use similar methods when they teach.
 
"Joan is one of the people who have done the most to bring people together" to revolutionize statistics teaching, says Garfield's colleague Robert delMas, an associate professor of educational psychology. "She's a catalyst."
 
The key to her success lies in never presenting statistics as a frightening or bewildering package of formulas. Instead, students collect their own data and analyze it to learn concepts first hand, making abundant use of computer tools to solve problems. Also, students get together in small groups to discuss their conjectures and test them with real or simulated data.
 
Since 1998 students have reported greater satisfaction with statistics courses in the department, and enrollments have been up. All seven doctoral students who have completed their doctorates and taken part in the department's statistics training program have found academic positions, and several were told that their unique statistics teaching was a factor in hiring them.
 
Two doctoral graduates of the program, Michelle Everson and Andrew Zieffler, are now colleagues of Garfield who have adopted and expanded her methods. In particular, Everson, now in her fifth year in the position, has emerged as a highly respected teacher in the same mold as Garfield.
 
Calming math phobia

Whenever Garfield or any of her colleagues remarks to a stranger on a plane or in an elevator that they teach statistics, the normal response is a groan.
 
"I think people fear statistics because they connect it with math," says Garfield. "But you can do very well in statistics and not be good at math."
 
Data reveals great statistics teachers abound
 
Garfield has received three teaching awards: Horace T. Morse Award for Excellence in Undergraduate Teaching (1995), the College of Education and Human Development's Distinguished Teaching Award (2002), and the Postbaccalaureate, Graduate and Professional Teaching Award (2006). Other University statistics teachers have also been recognized. Among them are Deborah Levison of the Humphrey Institute, who received an Award for Outstanding Contributions to Postbaccalaureate, Graduate, and Professional Education in 2006, and Jon E. Anderson of the University of Minnesota, Morris, who received a Morse-Alumni Award for Contributions to Undergraduate Education in 2003.
 
To remove the math phobia, Garfield shows students that they can succeed in statistics by thinking critically, without spending time manually crunching numbers. Take the "Let's Make a Deal" dilemma. On the basis of chance alone, a contestant has a two-thirds chance of winning by switching doors after the contents of one have been revealed. Garfield explains that originally, each door has a one-third chance of hiding a new car. However, the revelation of one door as a dud changes the odds. That is, if the contestant has chosen number three and number two is shown to be a dud, number one's chances of hiding the prize rise to two-thirds.
 
Everson, too, has helped students overcome their fears. One "math hater" student wrote of her: "Statistics is no longer the bitter enemy I avoided facing for so many years ... Michelle Everson is responsible for making this class worthwhile."
 
It's the real thing

To give students experience handling real data, Garfield has them measure body dimensions such as head circumference for everybody in the class. The students see that the variability in head sizes primarily reflects the diversity of the students' heads. But while the students all get measured once, every student in the class measures the instructor’s head. The variability in measurements of the teacher's head size reveals another source of variability, the "error of measurement." When they put their tape measures away, the students have gained a grasp of two key aspects of variability, the most fundamental concept in statistics.
 
In his classes, delMas has students work with the example of an actual company that laid off a number of workers, all over 55. What, he asks, are the chances that age played no part in the decision of whom to lay off? The answer has a strong bearing in the workers' age discrimination suit against the company.
 
"We try to show our students that statistics is a way of thinking about information--for example, in ads or in making decisions about weather forecasts and how they know the chance of rain," says delMas. "Or in evaluating data in order to buy a car. They should ask questions about how the data was collected. Why does one poll say [one thing], and another poll says the exact opposite? We hope students will become critical consumers."
 
The study of statistics also helps students overcome common misconceptions, such as the idea that correlation means causation. For example, says Garfield, a study of neighborhoods showed a correlation between income and the amount of recycling in a neighborhood. But that doesn't mean having more money makes people recycle more.
 
"Statistics is a fascinating subject," says Garfield. "It's been compared to detective work, investigating data to see what you can learn about the world."
 
 
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A riveting tale of the Titanic

By Deane Morrison
U of M News Wire
 
The night was plagued by human error, a disorderly rush to the lifeboats, and, of course, a nasty scrape with an iceberg. In the end, the Titanic took just two hours and 40 minutes to sink, snuffing out some 1,500 lives. Some have theorized that the ship's steel hull became brittle from cold and staved in on impact. But work by University of Minnesota alumnus Timothy Foecke suggested it was the rivets that were brittle and, perhaps, the key to the disaster.
 
Foecke tells the tale of the rivets in an upcoming book, CSI Titanic: A Forensic Examination of the Sinking, with coauthor Jennifer Hooper McCarty of Oregon Health and Science University. They conclude that the impact probably snapped off rivets like buttons torn from a shirt, opening the seams between the steel plates of the bow.
 
Examining 28 of these rivets, the authors found they had been made from substandard wrought iron. Wrought iron needs a little slag (a glassy byproduct of smelting) to fortify it, but too much makes it fragile. A combination of too much slag, insufficient mixing of iron and slag, and misoriented slag fibers left the rivets prone to snapping under pressure-a silent time bomb because there was no way to detect the weaknesses once the rivets were in place.
 
"If the rivets had been of better quality, the hull damage would have been smaller, and she would have sunk more slowly or even reached port in Halifax," says Foecke. With the rescue ship Carpathia only two hours away, a delay could have saved many lives.
 
Foecke holds a bachelor’s degree and doctorate in materials science and engineering from the University of Minnesota and is a staff materials scientist at the National Institute of Standards and Technology. He is currently involved in studies of metal structural failure during the World Trade Towers collapse. The Titanic book should be out by December, he says.
 
 
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Growing Concerns
A parenting question-and-answer column with Dr. Martha Erickson of the University of Minnesota

Question: My children recently broke some pottery garden sculptures in our neighbors' back yard on purpose and for no apparent reason. The kids told me about it, or I likely never would have known. How do I administer consequences for the vandalism without discouraging my kids from being honest with me? I don't want them to feel they'll be punished for telling the truth.
 
Answer:  This does pose an interesting dilemma of trying to teach two important and sometimes competing lessons: that honesty pays and that destructive acts nonetheless have consequences. Handled carefully, this situation offers an opportunity to teach both lessons in a way your children are likely to remember for a long time.
 
At this point, the reward for your children’s honesty will be pretty intangible, but important in the long run. They will need to hear from you, with warmth and sincerity, that you are glad they told you the truth and that you recognize it was courageous of them to do so. You might say, “It helps me learn to trust you when you are brave enough to tell me the truth even when it’s something that’s hard to tell me.” The fact that the children confessed to you indicates they know they were in the wrong. So acknowledge that by saying, “I know you understand that was a very bad thing to do, and I believe you won’t do something like that again.”
 
That said, you’re still left with a destructive act that calls for some logical consequences. To maximize your children’s learning you would be wise to engage your children in deciding with you what they should do to make amends to the neighbors. Start by asking them, “What do you think should happen now?” If that question is too broad for them to answer, encourage them to see through the neighbors’ eyes by asking them, “If someone broke something special that belonged to you, what would you want them to do?” With guidance -– if not on their own -– your children probably will arrive at two important conclusions: they need to apologize and they need to replace the objects they destroyed.
 
Although embarrassing, the apology is the easy part. Your kids may want to practice with you before they face the neighbors.  Depending on the value of the broken sculptures, and the ages and earning power of your children, making restitution may be challenging.  You probably will need to use your own money for now to purchase new sculptures for your neighbors, but you should work out a careful plan for having your children reimburse you for all or most of the cost over time.  Although it may take quite a while, a portion of their allowance each week could be put in a special container. You also might give the kids opportunities to do extra household chores to earn additional money. And finally, when the children have paid off their debt, you might have them write a note to let the neighbors know that restitution has been made.  
 
With clear, logical consequences, there’s no need for angry lectures.  Your children will have learned a memorable lesson about the value of property and the importance of facing the people they harm.  And when all is done, you can give the kids a hug and tell them you’re proud of the way they took responsibility for their actions -– and that you trust they won’t have to go through something like that again.