Wednesday, November 9, 2016

CNN, exit polls, and chi-square examples.

CNN posted a whole mess of exit polling data that illustrates how different demographics voted last night. And through my "I teach too many stats classes" lense, I see many examples of chi-square.

I think they work at a conceptual level to clearly illustrate how chi-square looks at people falling into different categories, then measures whether the distribution of people is by chance or not.

If you actually wanted to test these using chi square, I would suggest you should problem delete the other/no answer column (or else they will all come out as statistical significant, I would wager).

EDIT (11/14/16); Daniel Findley made of video demonstrating how to use Excel to conduct chi-square tests on the marital status data. Check it out here.


  1. Thanks for all your great suggestions. I put together a video based on your recommendations - because of the large sample size, I went into further analysis to show how the p-value changes as the sample changes.. If you have any thoughts/suggestions, I'd welcome any feedback you have.

    1. Looks great. I'll share the link with my readers and add it to this post.

    2. My only suggestion, and it is a little one, is label each table (is that expected data? Is it modified in some way?).

    3. Good suggestion, I'll update the associated excel file that can be downloaded.