Getting a Feel for the Meaning of "1 sigma", "2 sigma"..."5 sigma"

Scientific results are often reported in terms of a number of "sigma" from the expectation of the null hypothesis. Here, we look at the probabilities, under the null hypothesis, of a measured result falling 1 sigma, 2 sigma....5 sigma away from the null hypothesis prediction. We then relate these probabilities to the probabilities of more real-world phenomena: flipping a coin, choosing cards from a standard deck, the arrival of a 100-year storm, winning the lottery, and being hit by space junk.


Links mentioned in the video:


So, What Does "4.2 sigma" Mean? And What About "3 sigma" and "5 sigma"?:
   • So, What Does "4.2 sigma" Mean?  (And...  


Minicourse on Error Bars, Measurements, and Decision Analysis:
   • How We Know Stuff:  Minicourse on Err...  


Hypothesis Testing Playlist:
   • What's a P-value?  


What's a 100-Year Flood? Part I: Basic Definition:
   • What's a 100-Year Flood?  Part 1:  Ba...