Research Guides

SPSS

Chi-Square Test

The Chi-Square Test lets you compare categorical variables between groups:

  • Do men and women have similar opinions on sex education in public schools?
  • Do members of different religions have similar views on abortion?

 

To perform a Chi-Square Test in SPSS:

1. From the Analyze menu in SPSS, choose “Descriptive Statistics,” and then “Crosstabs.” A Crosstabs dialog box should appear.


2. Highlight each variable individually and move it to the row or column position by clicking the arrow transfer button. Generally, independent variables are placed in rows, and dependent variables in columns.


3. Click the Statistics button, located at the bottom of the Crosstabs window. A Statistics dialog box should appear. Select “Chi-Square” from the options in the Statistics and click “Continue.”


4. Click OK.

T Test

The T Test lets you compare continuous variables between two categorical groups:

  • Are gasoline prices in California the same as the national average?
  • Is average age the same between those who have/haven’t seen an X-rated film in the past year?

 

To perform an Independent-samples T Test in SPSS:

 

1. Choose “Compare Means” from the Analyze menu.

 

2. Choose “Independent-Samples T Test” from the options provided. An Independent Sample T test dialog box should appear.

 

3. Highlight the name of the dependent variable from the list appearing in the upper left corner of the window. Click the arrow transfer button to move it to the Test Variable(s) box.

 

4. Highlight the name of the independent variable from the list appearing in the upper left corner of the window. Click the arrow transfer button to move it to the Grouping Variable box.

 

5. Click on “Define Groups”. A Define Groups dialog box should appear. Provide variable values for two groups you're comparing.

 

6. Click OK.

ANOVA

ANOVA lets you compare continuous variables (usually averages of values) between three or more groups:

  • Do members of different ethnic groups have the same average income?
  • Do members of different religious groups watch the same number of hours of tv?

 
To perform a One-Way ANOVA in SPSS:

1. Choose “Compare Means” from the Analyze pull-down menu.

 

2. Choose “One-Way ANOVA” from the options provided. A One-Way ANOVA dialog box should appear.

 

3. Highlight the name of the dependent variable from the list appearing in the upper left corner of the window. Click the arrow transfer button to move it to the Dependent List box.

 

4. Highlight the name of the independent variable from the list appearing in the upper left corner of the window. Click the arrow transfer button to move it to the Factor box.

 

5. Click “Options” and select “Descriptive” from the list of statistics in this window. Then, click "Continue".

 

6. Click OK.

 

Correlation & Regression

Correlation & Regression Tests let you compare two or more continuous variables:

  • Is the number of hours spent watching tv related to someone’s age?
  • Is family income related to hours spent watching tv?

To perform a Linear Regression Test in SPSS:

 

1. Select “Regression” from SPSS’s Analyze pull-down menu and select the “Linear” option.

2. A dialog box for Linear Regression should appear. Move the independent and dependent variables to the appropriate boxes on the right by clicking the arrow transfer button.

3. Click OK.

Variables in SPSS

Nominal - unranked categories (sex, ethnicity, occupation, place of birth)

Ordinal - ranked categories (“on a scale of 1-5, how much do you agree with this statement…”)

Scale - numbers (# of pets, years of education, annual salary)

 Nominal and ordinal variables are sometimes called "categorical", while scale variables are called "continuous".