Snacking on Homework
Biology professor uses popcorn to teach her students about statistics
It’s 11 a.m. and a group of students are making popcorn in a microwave oven located on the fourth floor of the Fondren Science Building. It’s not snack time, though. It’s all part of a Southwestern biology professor’s unique way of helping her students learn statistics.
Romi Burks, associate professor of biology, has been using popcorn to teach statistics to students in her Methods in Ecology and Evolution class ever since the course was first offered at Southwestern in 2007.
Burks says she got the idea from a lab she herself had to do as a graduate student at Notre Dame. Her graduate school professor had borrowed it from a colleague who originally took a class from two famous statistics professors at the University of Wisconsin.
While the concept of using popcorn to teach statistics is not new, Burks has modified the approach to take into account the availability of microwaveable popcorn and the new individual-sized popcorn packets. She has even published her method in a society journal read by other professors focused on freshwater and marine research.
Burks says students who are interested in ecology need to know statistics more than students in other fields of science.
“Most ecology questions don’t have either/or answers,” she says. “The answers always come down to ‘it depends.’ Statistics enables you to come to a conclusion about the most important factors.”
Burks says she uses statistics for every experiment she does in her research, which focuses on an invasive species of apple snails known as Pomacea insularum.
Burks says microwave popcorn serves as a great model for a statistical exercise because of its versatility in flavors and sensitivity to different factors such as cooking time and the type of microwave used.
Her “popcorn statistics” exercise consists of four different labs done over the course of two and a half weeks. The exercise begins with each student selecting 3 or 4 different bags of popcorn to pop over the weekend. For each bag, the students have to measure the number of burned pieces, the number of edible kernels, the number of unpopped kernels, the length of five pieces of popcorn, the weight of the bag with the popcorn in it and the weight of the popped popcorn alone.
Once they have their data, the students spend the rest of the time using that data to generate a variety of statistics, tables and graphs. In the process, they work with difficult statistical concepts such as degrees of freedom, dependent and independent variables, analysis of variance, and regression and correlation analyses.
The exercise also teaches students important skills such as how to create a spreadsheet in Excel and how to use SPSS, a common statistical analysis program.
While all the students in her Methods in Ecology and Evolution class have already taken statistics, Burks says the popcorn statistics lab serves as a good way to refresh what they should have learned in statistics and apply it to hypothesis-driven science.
“I want them to see statistics not as a form of math, but as a tool biologists use,” she says.
Cameron Holland, a senior biology major, says he definitely feels the class is a great way of teaching statistics to aspiring biologists. “For many, statistics are intimidating, but by doing it with something more tangible than an abstract concept, it’s easier to visualize what you’re doing,” he says. “It’s also simple, which helps. You’re basically looking at how different microwaves, different times in the microwave, and different types of popcorn affect the number of kernels popped and the number of burned pieces. It’s something that everyone, regardless of their scientific or mathematic disposition, can relate to. That is vital when teaching something like statistics.”
Holland says the class helped him tremendously when it came to writing a paper for an independent study project he did while studying abroad in Australia last spring. Holland did research on coral crabs on the Great Barrier Reef and studied how coral bleaching affects the size and frequency of their egg clutches.
“With studies like that, being able to construct an experiment that you can test, and actually have the experiment tell you something, is important,” he says.
Holland says what he learned in the class also helped him explain to fellow students in his Methods in Cellular and Molecular Biology class this semester the meaning of some statistical tests that were mentioned in a paper the students were asked to read.
Burks says she plans to continue teaching the class for many years to come.
“I haven’t exhausted what you can measure using popcorn,” she says.