Could random variation alone account for the difference between the null hypothesis and observations from a random sample?
- A small P-value implies that random variation because of the sampling process alone is not likely to account for the observed difference.
- With a small P-value, we reject H0. The true property of the population is significantly different from what was stated in H0.
Thus small P-values are strong evidence AGAINST H0.
Oftentimes, a P-value of 0.05 or less is considered significant: The phenomenon observed is unlikely to be entirely due to chance event from the random sampling.