Section 14.2 Summary

1. In the sign test for the population median, each of the data values is converted to either a plus sign (+) or a minus sign (–). If there is a preponderance of plus signs to minus signs, or vice versa (depending on the form of the hypothesis test), then this is evidence against the null hypothesis.
2. In the sign test for the population median of the differences, for each matched pair, subtract the value of the second variable from the value of the first variable. We are interested only in the sign of the differences, not in the exact value of the difference itself.
3. The sign test for binomial data is a special case of the test for the population proportion for .