Nondirectional Hypotheses

A nondirectional hypothesis is a type of alternative hypothesis used in statistical significance testing. For a research question, two rival hypotheses are formed. The null hypothesis states that there is no difference between the variables being compared or that any difference that does exist can be explained by chance. The alternative hypothesis states that an observed difference is likely to be genuine and not likely to have occurred by chance alone. Sometimes called a two-tailed test, a test of a nondirectional alternative hypothesis does not state the direction of the difference, it indicates only that a difference exists. In contrast, a directional alternative hypothesis specifies the direction of the tested relationship, stating that one variable is predicted to be larger or smaller than null value, ...