P-value is the probability of -

• P-value: – Is the ‘Probability of Type I error’ (Null hypothesis is true but rejected) – Significance (a) level: is the maximum tolerable probability of Type I error – P- value is calculated (on basis of data while Alpha is fixed in advance: by the choice of level of significance employed in the test – P – value calculated can be less than, equal to or greater than alpha (a) – Keep Type I error to be minimum (P < a): Then results are declared statistically significant.