A paired-samples T Test compares the means of two variables/ measurements for a single group; or the means from two matched groups; within-subject design; repeated measures; or paired samples;
The Paired-Samples T Test procedure compares the means of two variables for a single group. The procedure computes the differences between values of the two variables for each case and tests whether the average differs from 0.
Example. In a study on high blood pressure, all patients are measured at the beginning of the study, given a treatment, and measured again. Thus, each subject has two measures, often called before and after measures. An alternative design for which this test is used is a matched-pairs or case-control study, in which each record in the data file contains the response for the patient and also for his or her matched control subject. In a blood pressure study, patients and controls might be matched by age (a 75-year-old patient with a 75-year-old control group member).
In our case, we will compares the means of two variables Year1 and Year2 which both are scores of students at different intervals to test and see whether the average differs from 0.
- To analyze the Paired-Samples T Test, click Analyze > Compare Means > Paired-Samples T Test.
- This dialog box will be opened.
- Move the Year1 and Year2 variables to the Paired variables textbox, Click Options and leave everything the same, and thereafter click on OK to see the results.
The results shows that the mean in the second year is higher compare to the first year, then there is a strong correlations between the participants who did well in the first year and are more likely to do better in the second year.