When you perform statistics, you are measuring or counting something. And sometimes the thing you want to measure is pretty straightforward. The number of sick days an employee takes. GPA. Parts per million of some thingy in the water.
But sometimes statisticians, especially psychologists, have to get a little creative and indirect with the way we measure a thing. Like the MMPI. IQ tests are our best bet at encompassing someone's intelligence but are still not perfect.
Sometimes, a statistician needs to find an approximation or proxy for the actual thing they are measuring. To explain this, show your students how the Federal Emergency Management Agency uses the Waffle House Index to determine how severely damaged a town is following a hurricane or tornado.
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| http://www2.philly.com/philly/news/weather/hurricane-florence-waffle-house-index-20180912.html |
If you are one of the uninitiated, Waffle Houses are an American chain restaurant. They are ubiquitous throughout the Southern United States (see a map of locations below).
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| https://locations.wafflehouse.com/ |
The origins of the WHI are delved into by the Economist here. And here is information from the Federal Emergency Management Agency.
How to use it in class:
-Again, when we are trying to come up with a good way to measure a thing, sometimes we need a proxy measurement.
-You can also use this as a conceptual example of using regression to make a prediction and NOT assuming causality. The government PREDICTS damage using the WHI but doesn't think Waffle House is the cause for the damage.