search

djnavarro / rbook

Source files for "Learning Statistics with R"
https://learningstatisticswithr.com
470 stars 156 forks source link

Kurtosis interpretation is dubious #26

Open djnavarro opened 4 years ago

djnavarro commented 4 years ago

Suggested I look at “Kurtosis as Peakedness, 1905–2014. R.I.P.” https://www.tandfonline.com/doi/abs/10.1080/00031305.2014.917055, referenced from Wikipedia: https://en.wikipedia.org/wiki/Kurtosis. Framing around “pointiness” or “peakedness” is the wrong way to describe it.

(courtesy: Błażej Kochański)

ampurr commented 1 year ago

Came here to report this and saw that you beat me to it by about three years. 😛

I took a stab at fixing it, but the section on kurtosis is surprisingly hard to edit. "Platykurtic," "leptokurtic," and "mesokurtic" refer to kurtosis > 0, equal to 0, and < 0, respectively. But they also refer to the pointiness of the curve. It seems you'd need to discuss misconceptions of kurtosis along with explaining what tailedness is.

My destructive inclination is to delete the whole section on kurtosis. As you mention, it doesn't really come up in psychology research papers anyway.