9.2 Understanding hypothesis tests
Hypothesis testing
9.2 Understanding hypothesis tests
Hypothesis testing
Favorable changes occurred in z-scores for weight (one-tailed p < 0.04) for age and gender among children in the combined center- and home-based intervention compared to comparison children at posttest.
Here is an example of a study that used an one-tailed test as opposed to a two-tailed test.
Challenge for readers: Dig into the Methods section and find out why the researchers used an one-tailed test.