P-hacking.

Back to basics. I’ve been reading and hearing a lot in the news/podcasts about p-values and “p-hacking” (more that here, here, here, here).

How would you explain what p-value is to a sixth grader? Difficult to describe something technical in a simple way. The best explanation I read was from this FiveThirtyEight article:

Imagine, he said, that you have a coin that you suspect is weighted toward heads. (Your null hypothesis is then that the coin is fair.) You flip it 100 times and get more heads than tails. The p-value won’t tell you whether the coin is fair, but it will tell you the probability that you’d get at least as many heads as you did if the coin was fair. That’s it — nothing more.

Also regarding tradeoff between intuitiveness and accuracy:

Try to distill the p-value down to an intuitive concept and it loses all its nuances and complexity… You can get it right, or you can make it intuitive, but it’s all but impossible to do both.

Check out the full article at fivethirtyeight.