What Does the p-Value Mean?
Summary: The p-value tells you how likely it is to get the sample you got (or a more extreme sample) if the null hypothesis is true. Many people are confused about the p-value and try to read too much into it. In your experiment, you got a certain set of results, like a sample mean. The hypothesis test asks whether random chance can account for those results if the null hypothesis is true. The p-value is the likelihood, if H0 is actually true, that random chance could give you the results you got. It is a conditional probability: p-value = P(this sample | H0 is true) When you write it in symbols like that, you can see right away that the p-value is not the probability that either hypothesis is true or false: • The p-value is not the probability that H0 is true. • The p-value is not the probability that H0 is false. • The p-value is not the probability that H1 is true. • The p-value is not the probability that H1 is false. • The p-value is not the probability that your results are due t
