Sunday, January 14, 2018

The Economist's "What's the most common form of contraception?"

This video provides an example of mode when it reveals survey data about the most common for of birth control used by married women or women who live with their partners. Before revealing the answer, they have strangers sitting in a produce department of a grocery store discussing their best guess for the answer? Huh? Well, at least you get to listen to strangers awkwardly talking about pulling out in front of a bunch of vegetables.

I think that traditionally aged college students are a little surprised by the modal response: Sterilization. This opens up the opportunity to talk about the sampling: They could only survey women who are electing to use birth control (so, not trying to get pregnant) AND in a long term relationship, so a more permanent form of family planning is probably more attractive.

Tuesday, January 2, 2018

"Draw My Data" and a bunch of other stuff for teaching correlation.

Robert Grant's website Draw My Data provides you with a blank scatter plot graph. You add your dots, and the website generates M and SD for your X and Y, as well as r for the relationship between X and Y. It even generates a data set for download.

My twitter handle, @notawful, has an r of -.485. Via

Great for illustrating a specific kind of relationship (positive, negative, etc.) to your students. Also allows for much goofiness. Like Alberto Cairo, who plotted a T-rex and went viral.

And then the T-rex plot, and a bunch of other plots, were used to create an animated, updated version of Anscombe's Quartet. And that was presented at a conference by Matejka & Fitzmaurice.

So, lots of stats goodness here. You can let your students play with Draw Your Data, or use that website to generate data sets for use in class. You can also use the dino data to illustrate why it is important to graph out data.

Monday, December 18, 2017

Stein's, "Could probiotics protect kids from a downside of antibiotics?"

Your students have heard of probiotics. In pill form, in yogurt, and if you are a psychology major, there is even rumbling that probitotics and gut health are linked to mental health.

But this is still an emerging area of research. And NPR did a news story about a clinical trial that seeks to understand how probiotics may or may not help eliminate GI problems in children who are on antibiotics. Ask any parent, and they can tell you how antibiotics, which are wonderful, can mess with a kid's belly. When they are already sick. It really can be the worse.

Science is trying to provide some insight into the health benefits of probiotics in this specific situation. They spell out the methodology:

How to use in class:

1) I love about this example is that the research is happening now, and very officially as an FDA  clinical trial. So talk to your students about clinical trials, which I think you can then related back to why it is good to pre-register your non-FDA research, with explicit research methodology, outcome measures, etc.

2) I think this example also illustrates the slow, iterative process of science. Sure, other research has investigated probiotics. But this research is specifically investigating children, using a specific probiotic, and measuring very specific outcomes, like instances of GI problems, fecal samples, and pediatric quality of life.

3) You could even use this to explain an independent t-test. Two groups of kids, one gets the yogurt with probiotics, other group gets placebo yogurt. And then they measure something at the end. Clearly, the actual research isn't a t-test as their are multiple outcome measures, but it is still a conceptual example.