“We needed a shorter word to describe, and p-dash-something seemed to make sense,” Simmons says. At a psychology conference in 2012, Simonsohn gave a talk in which he used the term p-hacking for the first time. The problem, as the Beatles song experiment showed, is that this kind of fiddling around allows researchers to manipulate their study conditions until they get the answer that they want-the grownup equivalent of kids at a slumber party applying pressure on the Ouija board planchette until it spells out the words they’re looking for.Ī year later, the team went public with its new and better name for this phenomenon. By convention, a p-value of less than 0.05 gives the researcher license to say that the drug produced “statistically significant” reductions in blood pressure. A p-value of 0.05 means there’s only a 5 percent chance of that scenario. The p-value is the probability that you’d find blood pressure reductions at least as big as the ones you measured, even if the drug was a dud and didn’t work. Suppose you’re testing a pill for high blood pressure, and you find that blood pressures did indeed drop among people who took the medicine.

The p refers to the p-value, a ridiculously complicated statistical entity that’s essentially a measure of how surprising the results of a study would be if the effect you’re looking for wasn’t there. Results from a study can be analyzed in a variety of ways, and p-hacking refers to a practice where researchers select the analysis that yields a pleasing result. Metascience nerds rejoice! The term p-hacking has gone mainstream. It’s got an entry in the Urban Dictionary, been discussed on Last Week Tonight with John Oliver, scored a wink from Cards Against Humanity, and now it’s been featured in a clue on the TV game show Jeopardy.

Data dredging vs p hacking