EXAMPLE 12.18

A comparison of interest. The researcher hypothesizes that participants exposed to a negative Facebook profile would spend more time viewing the page than would participants who are exposed to a positive Facebook profile. Because two groups are exposed to negative profiles and two are exposed to positive profiles, we can consider the following null hypothesis:

673

versus the two-sided alternative

We could argue that the one-sided alternative

is appropriate for this problem provided other evidence suggests this direction and is not just what the researcher wants to see.