Compare Means When the Values Are Paired (A Paired t-Test)

How To... > Work with Statistical Objects > Test Hypotheses > Compare Means When the Values Are Paired (A Paired t-Test)

When you have two sets of values that are paired, using a compare means test would throw away the information that the values are paired. Instead, construct a new attribute that computes the differences for each case. Then use a test mean to decide if the difference is significantly different from zero (or whatever value you hypothesize).

This is shown below for an example in which we have a random sample of student test scores before and after a unit of instruction.