By default, Column Comparisons test all non-NET categories within a row and within a Span. This article describes how to specify which columns you want to compare, rather than doing all possible column comparisons.
For example, let's say I want to do a column comparison of the following table to see which percentages are significantly different from each other...
...but rather than doing all possible column comparisons, I only want to compare Columns A vs B; B vs C; and C vs D.
A table on which you want to perform column comparisons.
- Select a table
- If column comparisons are not already enabled, go to the object inspector on the right and select Properties > Significance > Compare Columns
By default, you get all possible paired comparisons, but we needed to take this step to get the Column Names at the bottom of the table. You will need these names to define your custom column comparisons.
- Select a column in the table. It does not matter which one you select. If using a table with spans or a banner, select the span you want to modify.
- In the Object Inspector, select Properties > Significance > Advanced> Column Comparisons.
- At the bottom of the dialog, click Custom
Custom overrides Displayr's default choice of columns to compare and allows to you enter the specific groups of column letters to compare. This can be done for the entire table, when there are no spans or Recycle column letters is unchecked in the Statistical Assumptions settings or for an individual span, if that span is selected in step 1. The default setting includes all possible paired comparisons. If you enter "A/B, A/C" then only two significance tests will occur within the span: A vs B, and A vs C. B and C will not be tested against one another.
In our case, we want to compare adjacent age groups, so we will enter "A/B, B/C, C/D".
- In the Custom box, enter "A/B, B/C, C/D"
- Select Apply to Selection to apply it to just this table or Apply as Default to make it the default for all crosstabs with date variables in the document.
If you select, Apply to Selection, these comparison settings will be saved with the variable set used in the columns and will appear anywhere this variable set is used in the entire document.
The results are as follows:
- Optional: To see which columns are being compared in the table, select Columns Compared in the Inputs > STATISTICS >Below menu the object inspector on the right.