There is a tremendous amount of confusion around what a p-value actually is, despite their widespread use in science. Here is my attempt to explain the concept of p-values concisely and clearly (including why they are useful and what often goes wrong with them). — What's a p-value? — If you run a study, then (all else equal, aside from rare edge cases) the lower the p-value, the lower the chance that your results are due to random chance or luck. More precisely: a p-value is the probab...