1. Differentiating between directional and non-directional hypotheses

2. Non directional – also called two tailed Experimenter predicts that two groups will be different; but doesn’t say in what direction Ho: μ1 = μ2 (null hypothesis) H1: μ1 ≠ μ2 (alternative hypothesis)

3. Directional Experimenter predicts that one group will do better than the other (in this example E predicts that group 1 will be greater than group 2) Ho: μ1 ≤ μ2 (null hypothesis) H1: μ1 > μ2 (alternative hypothesis – this is the experimenter’s prediction)

4. Directional prediction If E predicts that group 1 is less than group 2 then: Ho: μ1 ≥ μ2 (null hypothesis) H1: μ1 < μ2 (alternative hypothesis – this is the experimenter’s prediction)