Reporter > Applying statistical tests > Net difference test > Details and restrictions of the net difference test
 
Details and restrictions of the net difference test
Columns to be tested must be defined in groups of four. If there are more than four categories the net difference test is carried out on the preceding four category elements nearest the net difference element. If there are fewer than four categories, the net difference test is not carried out. The net difference test is not available across the different sections of a table that are created by nesting and concatenation.
When you specify a net difference test, you must also add a net difference element to the top of the table. If the table is nested, this must be in the innermost nesting level.
Notes
The Paired Preference and Net Difference tests will not calculate successfully until the Paired Preference or Net Difference properties are added, as shown below:
Solution 1 (Paired Preference and Net Difference)
Paired Preference
TableDoc.Tables["Table5"].Statistics.Add("PairedPreference")
TableDoc.Tables["Table5"].Statistics.PairedPreference.SigLevel = 5
TableDoc.Tables["Table5"].Statistics.PairedPreference.SigLevelLow = 10
Net Difference
TableDoc.Default.Statistics.Add("NetDifference")
TableDoc.Default.Statistics.NetDifference.SigLevel = 5
Solution 2 (Net Difference)
Select Tables > Properties > Statistics > [Net Difference]
See also
Net difference test