P-Value

P-value is a way to express the likelihood that H₀ is not true.

The largest significance level at which we would accept the null hypothesis. It enables us to test hypothesis without first specifying a value for α. OR

The probability of observing a sample value as extreme as, or more extreme than, the value observed, given that the null hypothesis is true.

If the P-value is smaller then the significance level H₀ is rejected. If it is larger than the significance level H₀ is not rejected.

If the P-value is less than

1. 0.10, we have some evidence that H₀ is not true
2. 0.05, strong evidence that H₀ is not true
3. 0.01, Very strong evidence that H₀ is not true
4. 0.001, extremely strong evidence that H₀ is not true