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 ...

The Washington Post , and numerous other media outlets, recent wrote about an unintended consequence of COVID-19 and the sudden drop off in commercial flights: Fewer data points for weather forecasts ( PDF ). Due to the coronavirus, commercial flights are down: How does this affect weather forecasts? Data is constantly being collected from commercial flights, and that data is used to predict future weather: Ways to use in class: A conceptual example of multivariate modeling : Windspeed...temperature...humidity...lots of different data points, from lots of different elevations, come into play when making our best guess at the weather. This is a non-math, abstract way to discuss such multivariate models. A conceptual example of effect sizes/real-world effects: In the article, they clearly spell out the magnitude of the data loss. That is pretty easy to track since we can count the number of flights that have been canceled. More complex is determining the effect size of this data loss....

Hi! This post is a change of pace. Instead of providing an example to use in stats class, I'm going to share how I incorporated text-message based class discussion in online courses with the GroupMe App. Doing so was a big win for me during a hard semester, I hope it is a big win for anyone who happens to read this post and use GroupMe in the future. My experience using GroupMe App to facilitate class discussion during The Rona My goals for OL SP20: I wanted my students to learn. I wanted to preserve the best parts of my classes. I didn't want my classes to be another burden in a stressed out world. During March 2020, I wast teaching Introduction to I/O Psychology. It was a class of 20. My students were mostly Juniors and Seniors, who were either psychology majors or minors. On our last day of f2f class, when we knew that we were going to transition to OL, I asked my students to reserve our normal 12:20-1:25 MWF meeting time for the class. I wanted my students to continue to h...

Katherine Baicker ,  Oeindrila Dube ,  Sendhil Mullainathan ,  Devin Pope,  and  Gus Wezerek created an interactive, data-driven piece for NYT . It provides a new perspective on how we should proceed with re-opening businesses during the COVID-19 pandemic. They argue that we must consider 1) how long people linger in different types of stores, 2) how often they visit these stores, 3) the square footage of the stores, and 4) the amount of human interaction/surface contact associated with how we shop at different stores.  How to use this in class:    1) Show your students how data can inform real-life problems. Or crises, like how to safely re-open stores during COVID-19. 2) Show your students how data can be used in creative ways to solve problems. The present argument uses cellphone location data. 3) Show your students data viz in real life: Here, scatterplots that really improve the #scicomm potential of this piece. 4) Show your students the rese...

This brief video from NPR (they make videos, what?) describes how the CDC will be randomly sampling Atlanta residents to test for COVID-19 antibodies. The efforts hope to provide a better estimate of the spread of the disease. H/t to Sy Islam for sharing this with me. I think you could use this in class as a super-fast example of how we use samples to generalize about larger populations. The CDC is sending out employees to conduct antibody tests on a random sample of Atlanta residents. The tests are meant to show how many people have been infected with the coronavirus. pic.twitter.com/mXqznHUJmV — NPR (@NPR) April 29, 2020

Hi! Here is an easy-to-use review of regression, with a regression example. I posted about using this catty tweet to teach regression previously: Right? Do you see the regression? Every wife has two data points: Year she gets married, and the year she was born...and from that, you can perform a regression to predict when Quaid would actually marry someone who has not been born yet (2052). Well, I decided to make it into a whole Google Slides presentation for this example, with links to data, to use as a regression review during the quarantine. Admittedly, the example is ridiculous, and the sample is far too small to run a reliable regression. That being said, I think the example is vivid and sticks. I also think it does an excellent job of illustrating how the equation can be used to make predictions. Additionally, I genuinely find meaning in helping out my fellow statistics instructors in good times, and doubly so during this challenging semester. Feel free to view my pres...

Here are two good review examples for chi-square, one for goodness-of-fit, and one for the test of independence. Here is my Google Slide presentation, which includes links to data sets for the examples. One features Taco Bell . The other features actual Developmental Psychology research, as featured on NPR . When I use these in class, the students have already been introduced to chi-square, have been walked through examples of both chi-squares, and then they analyze the data on their own using JASP. Y