Statistics - explanations and formulas

P Value

P value is the probability of getting the results you did given that the null hypothesis is true. Put simply it’s the chance that the relationship you are observing is observed by pure chance. So if you obtain a p-value of 0.01, it means that there is a 1% chance that the relationship between the experimental group and the control group doesn't actually exist.  It is important to note that a p value is attempting to show a statistically significant difference, but it does not show the magnitude of effect (ie place example here from the article) or show the direction of the difference.  This is why data like Odds Ratios, Hazard Ratios, NNT or more useful statistics than a p value.

A p value determines the difference between 2 groups.