Q-Test (Cochran)
The Cochran Q-test is a comparison of more than two dependent variables which measure "the same thing" on the same object under different conditions. The variables must be dichotomous, that is, allow only two answers (such as a yes/no question). Example: Headache patients are given three different treatments. Each patient undergoes all three treatments at different times, and responds "effective" or "not effective" to each one. This is an extension of the McNemar test, for which an example is given here.
The Q-test calculates a chi-square statistic for the differences in response. The P-value reflects the significance of the difference.