Test statistic - Numerical value produced by a statistical formula that is used to test the assumption about the population parameter described in the null hypothesis. One tailed test has 1 critical value. Two tailed test has 2 critical values. P value - P value is the observed level of significance associated with the calculated value of a test statistic. P value for x is what the level of significance would be if x were a critical value.
P value depends on type of rejection area, left tail, right tail, two tail.
Probability that test statistic would fall within this region is very likely if null hypothesis is true. Area of rejection - Values of test statistic that will indicate that the null hypothesis should be rejected. Also referred to as the probability of not rejecting the null hypothesis when it is true. Also referred to as the probability of committing Type I error, also referred to as alpha. Outline of Hypothesis Test Methodology.