Today's post is one, small, to-the-point example of sampling bias. On May 27, 2020, my family and I were awaiting lift-off for the (subsequently grounded) NASA/SpaceX launch. To no one's surprise, I was following NASA on Twitter during the hoopla, and I noticed this Tweet: https://twitter.com/NASA/status/1265724481009594369 And I couldn't help but think: That is some sampling bias. Admittedly, their sample size is very impressive, with over 54K votes. But this poll went out to a bunch of people who love NASA so much that they follow it on Twitter.  What is a less biased response to this question? As always, Pew Research Center had my back. 58% of Americans responded that they definitely/probably weren't interested in traveling into space: https://www.pewresearch.org/fact-tank/2018/06/07/space-tourism-majority-of-americans-say-they-wouldnt-be-interested/ If you want to expand upon this example in class, you could ask your students to Google around for information on the ...

In addition to being an astronaut, Scott Kelly is one-half of a pair of twins and a lab rat for NASA researchers studying space travel's effects on the human body. This NPR story details how NASA has been using twin research to learn more about the side-effects of prolonged time in space as the agency prepares to go to Mars. Scott and his twin, Mark (also an astronaut!), have been providing all manner of biodata to researchers. In particular, researchers are interested in the effects of weightlessness and exposure to space radiation on aging. This story provides a good example in class, as you can discuss twin AND longitudinal research. I think you could also use this example to introduce the concept of paired t -tests. UPDATE 2/9/2017: Preliminary research is available if you want to flesh out this example.  MOAR UPDATES 3/3/21: CHECK OUT this PBS documentary featuring the twins! ESPECIALLY useful for a brief class period: This 2-minute clip that describes the twin ...