Significance level
Performing hypothesis tests through interpretation of p-values and through decision rules with fixed significance levels are closely related.
Although some of the underlying theory depends on the type of test, the decision rule for any test can be based on its p-value. For example, for a test with significance level 5%, the decision rule is always:
Decision | |
---|---|
p-value > 0.05 | accept H0 |
p-value < 0.05 | reject H0 |
For example, to conduct a test with significance level 1%, the null hypothesis, H0, should be rejected if the p-value is less than 0.01.
If computer software provides the p-value for a hypothesis test, it is therefore easy to translate it into a decision about whether to accept (or reject) the null hypothesis at the 5% or 1% significance level.