What does a p-value indicate in hypothesis testing?

A p-value in hypothesis testing is a measure that helps determine the significance of the results observed in a study. Specifically, it indicates the probability of obtaining the observed results—or results more extreme—given that the null hypothesis is true. In other words, it reflects how likely it is to see the data you collected if the null hypothesis (which typically states that there is no effect or no difference) is indeed correct.

A low p-value suggests that the observed data would be unlikely under the assumption of the null hypothesis, which can lead researchers to reject the null hypothesis in favor of an alternative hypothesis. Conversely, a high p-value indicates that the observed data is more consistent with the null hypothesis, suggesting that there isn't strong evidence against it.

This understanding is essential for researchers when they interpret their statistical findings and decide whether to reject or fail to reject the null hypothesis based on the evidence provided by their data.