Independent Z-Tests

The Independent Z-Test tests the significance of the differences between percents for selected columns, a test between independent proportions (for example, males versus females or between age groups). You choose if the calculation should use pooled or unpooled proportions.

Statistical testing between percents applies to the percent displayed. If more than one percent is displayed (for example, vertical percent and horizontal percent), the statistical testing applies to the vertical percent. If vertical percent is not displayed and more than one percent is displayed (for example, horizontal percent and constant percent), the statistical testing applies to the horizontal percent.

Statistical testing between percents only applies to constant percents if constant percent is the only percent displayed and if the statistical test being done is an independent test (Independent (using unpooled proportions) or Independent (using pooled proportions)).

Select one of the following tests:

Independent (using unpooled proportions) - (Default)
Independent (using pooled proportions)

Z-Test Options

Confidence Levels

Select one or two confidence levels for the chosen test.
You can choose 1 or 2 confidence levels from the pre-listed percentages or specify custom confidence level percentage(s).
WinCross will not allow you to specify a pre-listed percentage and specify a custom confidence level percentage.

Options

Select Show significance indicators in banner if you want the significance annotation displayed for each banner column.
Select Exclude 0% cells from analysis if you don't want to include cells that are 0% in calculations for percentage tests.

When a "Total" column is being used and denoted as such in a comparison group, given the possibility of finding "significant" differences due only to the degree of overlap of the part to the whole (Total), WinCross has adopted the safeguard of declaring all such differences not significant if the fraction of the part to the whole is less than 5% or greater than 95%.