Graziano & Raulin
Research Methods (9th edition)
Testing Hypotheses
with Ordered Data
The appropriate inferential statistic for ordered data is the Mann-Whitney U-test. The procedures for computing this statistic can be found in virtually any undergraduate statistics text in psychology. Unfortunately, this test can only be performed with two groups. Because the available inferential statistics for ordered data are so limited, it is in your best interest to try to avoid using ordered data. The statistical procedures are more powerful and there are greater options if you can use dependent measures that produce score data.
Are there any other hypotheses to be tested?
If so, press the RETURN button;
otherwise, press the PROCEED button.