How to Specify Columns to be Compared in a Table

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. These settings are accessed by selecting any column header specifically, instead of selecting the entire table, before entering the Significance > Advanced settings. Any changes you make to the specific columns tested are linked to the variable set will appear in all tables where that variable set is used in the columns. While this article focuses on the comparison settings for the variable set, you should also review other information in the Requirements section to ensure your other testing assumptions are in line with how you want to test.

This article covers how to:

• Compare within span including NETs
• Compare custom within span
• Compare all columns
• Compare custom columns on the entire table
• Compare columns against the Main NET

Requirements

• A crosstab with multiple columns, without a Date/Time question in rows/columns. These examples use the following table:

  

• Understanding How to Apply Significance Testing in Displayr as the Default or Apply to Selection.
• Compare columns selected in the Appearance > Appearance > Significance menu - this turns on stat testing and shows the column names at the bottom of the table.
• An understanding of the Column Comparisons > Overlaps setting, see Overlaps for more info. If changing to either Dependent or Independent, you will also need to change Test Type > Proportions/Means test to something other than Non-parametric.
• An understanding of the Column Comparisons > Multiple Comparison Correction settings; see How to Apply Multiple Comparison Correction to Statistical Significance Testing.

Method - Compare within span including NETs

1. Select a column header (this allows you to set comparisons for this specific variable set) and from the object inspector, go to Appearance > Appearance > Significance > Advanced dialogue.
   
    
2. Because respondents in the NET column completely overlap with respondents in other columns, you will need to set  Column Comparisons > Overlaps to either Dependent or Independent, depending on what types of tests you'd like to run.
3. In the Compare section, check the Compare within spans > Include NETs box. Note, if you only want to include the NET on some of the spans, see the next section to compare custom within span.
4. You will also need to change Test Type > Proportions/Means test to something other than Non-parametric.
5. Click Apply to Selection or Set as Default to close the window (this refers to settings outside the Column Comparisons > Variable Set - Compare section).

Now you will see the NET columns are tested against the other columns within the span:

Method - Compare custom within a span

1. You can only customize testing custom columns within one span at a time. Select one of the lowest-level column headers within the span you want to customize and go to Appearance > Appearance > Significance > Advanced in the object inspector.
   
    
2. In the Column Comparisons > Compare section, check the Custom within span.
3. In the space to the right, specify which columns to compare using the column names and /. To have multiple configurations, you can separate each test by a comma. Note that you must specify columns within each span. For example, to test the Age columns custom where column A is only tested against the NET (D), but the other columns are all tested against each other, you would use:
   A/D, B/C/D
   
4. If including NET columns in the custom tests, be sure to review other settings to change in Compare within span including NETs.
5. Click Apply to Selection or Set as Default to close the window (this refers to settings outside the Column Comparisons > Variable Set - Compare section).

Now you will see the custom tests in the second span below:

Method - Compare all columns

1. If your table has spans, you have two options to allow the testing access to all columns:
   1. Delete the spans.
   2. Don't recycle column names (this is described in more detail below).
2. Select a column header (this allows you to set comparisons for this specific variable set) and go to Appearance > Appearance > Significance > Advanced from the object inspector.
   
    
3. If your table has spans, on the Column Comparisons tab, uncheck Recycle column letters.
4. In the Column Comparisons > Compare section, select All columns and Include NETs (if needed).
   
5. If you're including all columns on a banner or binary-multi variable set, it's likely some will have overlapping respondents. Be sure to review other Overlaps and Test type settings to change in Compare within span including NETs.
6. Confirm your Multiple Comparison Correction settings, see Requirements above.
7. Click Apply to Selection or Set as Default to close the window (this refers to settings outside the Column Comparisons > Variable Set - Compare section).

Now you'll see the tests encompass all columns on the table:

Method - Compare custom columns on the entire table

If working with spans, a banner, or other overlapping data in the columns, or you want to include NETs:

1. See full instructions in Method - Compare all columns EXCEPT for step 4, which selects All columns.
2. For step 4 in the method above, set up custom tests using the example in step 2 below.

If your table has a Nominal or Ordinal variable in the columns (meaning the categories are mutually exclusive):

1. Select a column header (this allows you to set comparisons for this specific variable) and go to Appearance > Appearance > Significance > Advanced dialogue.
2. Instead, in the Column Comparisons > Compare section, select Custom, and in the space to the right, specify which columns to compare using the column names and /. To have multiple configurations, you can separate each test by a comma.  
   
   

You'll see those specific tests are being run:

Method - Compare columns against the Main NET

See How to Include the Main NET Column in Column Comparisons.

Additional Notes

Because specifying columns to be tested is on a variable set level, the same columns will be compared on all tables using the variable set. If you need some tables to compare different columns, you will need to Duplicate the variable set and modify the columns to compare on the duplicate version. If you do not see the variable set's Compare section on the Significance > Advanced > Column Comparisons tab, be sure that you click on one of the column headers (on the lowest level if nested) before opening the settings.

Next

How to Apply Multiple Comparison Correction to Statistical Significance Testing

How to Apply Significance Testing in Displayr

How to Compare Significant Differences Between Columns