Creating a Tukey mean-difference plot

Summarize the differences between two related observations.

1. Select a cell in the dataset.
2. On the Analyse-it ribbon tab, in the Statistical Analyses group, click Compare Pairs, and then click Difference.
   The analysis task pane opens.
3. If the data consists of paired/repeated measurements in separate variables:
   1. In the Model drop-down menu, select Paired/Repeated.
   2. In the Y list, select the quantitative variables.
4. If the data consist of matched pairs with a separate response variable, factor variable, and blocking variable:
   1. In the Model drop-down menu, select Matched.
   2. In the Y drop-down list, select the quantitative response variable.
   3. In the X (factor) drop-down list, select the categorical factor variable identifying the groups.
   4. In the Block drop-down list, select the blocking variable identifying the matching.
5. Optional: To show a histogram of the distribution of the differences, select the Histogram check box.
6. Optional: To show a normality plot of the differences, select the Normal plot check box.
7. Click Calculate.