Source: Image of P-value graph p-value Graph, Creative Commons: p-value graph: http://en.wikipedia.org/wiki/File:P-value_Graph.png
A value that can be compared to the test statistic to decide the outcome of a hypothesis test
The probability that the test statistic is that value or more extreme in the direction of the alternative hypothesis
A measurement, in standardized units, of how far a sample statistic is from the assumed parameter if the null hypothesis is true