Describing the credibility of the null hypothesis

In the previous page, a diagram with scales illustrated how the evidence against H0 was 'weighed' for different data sets. A p-value is a numerical description of this evidence that can give a scale to this diagram.

A p-value is a numerical summary statistic that describes the evidence against H0


Market share estimation through audits

In the example on the previous page, two different auditing methods were used to estimate market share. Is there any difference between the mean estimate of market share for the two methods?

The diagram below weighs the evidence using the p-value from a t-test of whether the mean difference, µ = 0.


The p-value is an index of credibility for the null hypothesis, µ = 0.


P-values have the same interpretation for all hypothesis tests.