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Factorial ANOVA, Tai Chi, and the importance of base rates

I love JAMA Visual Abstracts. I have blogged about them before. They are great ways to illustrate 1) basic, intro stats topics, 2) excellent sci-comm, and 3) psych-adjacent medical examples. 

I learned about a recent JAMA publication on NPR (which you could play for your students). It compared blood pressure in people who were in a Tai Chi exercise condition versus an aerobic exercise condition:


https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2814872

Here are some ways you could use it in class:

1. Simple factorial ANOVA research design. Two groups with a repeated measure design makes me think "factorial ANOVA." 

I have not, but it would be easy to make a 2 x 2 bar graph with this data (the actual data is embargoed until December). 




2. Active control group: The control group wasn't sitting on a couch. The control group was doing aerobic activities. 

3. Lots of outcomes and potential for significance (and Type II error): The main thrust of this paper is all about blood pressure. But they collected a crap low of other data as well. Many didn't pan out (which they own and share in their supplemental material). 



4. Making the best data viz choice: There are no data image police but maybe there should be. Why not show this as jitter plots (to capture variability)

5. Cross-cultural health psychology: Not all of your examples have to be pure psychology examples. This one, in particular, demonstrates a) health psychology and b) the importance of cross-cultural research in studying interventions rooted in culture (like Tai Chi in China). 

6. The importance of base-rates: Base-rate, pre-study data is important when telling the difference between two groups, and they collected that data here:



ALSO: If you like this example, imagine a whole textbook filled with these sorts of examples. A textbook written by ME, published by WW Norton, and available for Spring 25 adoptions. If you want more information, sign up for my mailing list.

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