How to Significance Test One Variable By Another

This article describes how to test for significant differences between two questions. For example, supposeyou want to test for differences between two questions: "Have you ever eaten at the following restaurants" and "Have you ever considered eating at the following restaurants".

To do so, they must first be combined into a binary grid like the one below:

Requirements

Two categorical variables with the same categories.

Method

Combining the Q3 and Q4 into a single variable

In this example, we will be using two variables, Q3 and Q4. Before beginning, we will create duplicate copies of each variables:

From the Data Sets tree, select variables Q3 and Q4
Right-click the highlighted area and select Duplicate.

The two duplicates are still highlighted.
Right-click one of the highlighted variables and select Combine

Remove unnecessary categories

The category None of these is a category of the Consider Eating At... variable but not the Ever Eating at... variable so we will remove it. We will also remove the Other fast food category because it is non-specific.

Right-click the combined variable, and from the menu, select Reset > Table Categories
Select all the categories, and then Contol-Click to unselect the None of these and Other fast food categories
Right-click the highlighted area and select Combine

Change the variable names

Each variable names is repeated twice so it is hard to tell whether they came from the "Have you ever eaten at..." questions or the "Have you even considered eating at..." question. We will use Wildcards to make the renaming process a little easier. Click here for more information on how to use Find and Replace in Displayr

Select the all the variables, right-click and select Split
Select the first set of variables
In the toolbar, type * in the search box and then click This Document
On the left, select ADVANCED and check the Use Wildcard box
Select Replace and in the Replace with box and type Eaten at ${0}
Under FIND IN, check the Only search selected items box
Click Replace All
Select the second set of variables
In the Replace with box, type Considered ${0}
Click Replace All

Next we will get rid of the number "1" at the end of these variable names
In the search box at the top of the screen, replace the * with 1
Remove whatever is in the Replace with box
Click Replace All