Graziano & Raulin
Research Methods (9th edition)
Chi Square Test for Independence
We will illustrate the chi square test for independence using the data from Table 5.2. We have entered the information from this table into a SPSS data file and saved the file elsewhere on this Student Resource Website. We will test to see whether men and women differ in their political affiliations.
We start by opening the SPSS program and loading the Table 5.2 data file, which gives us this screen. The chi square test for independence is performed in the crosstabs section. To get to that section, select the Analyze menu, the descriptive statistics submenu, and the crosstabs choice, which gives you this screen.
You want to set up the analysis as if you were doing a cross-tabulation of sex by political affiliation. So we will move the variable of sex to rows box and party affiliation to the columns box, as shown in this screen. Actually, it does not matter which of the variables go in which box, as long as one goes in one box and the other in the other box.
To compute a chi square test for independence, you click on statistics, which opens this screen. You select the chi square option as shown, click continue to return to the crosstabs box, and then click OK to run the analysis, which gives you this screen.
The chi square value for this analysis is 4.86, with 2 degrees of freedom. The p-value for this chi square is 0.88, which falls short of the traditional alpha level of .05. Therefore, we fail to reject the null hypothesis that men and women do not differ on the pattern of party affiliations.
Animations
We have prepared an animation that will walk you through this procedure. To run the animation, simply click on the title of the animation in the table below.
Note that we do not recommend that you try to run the animations if you have a slow connection, such as a dial-up connection. You will find that the animations take forever to load with a slow connection.