The APA (the American Psychological Association) has specific rules and guidelines for how to report results of research. Psychologists use the Chi-Square test to compare the frequencies of events or responses. This statistical test which can be conducted on a single sample (i.e., people responding at two different times or to two different stimuli) or on multiple samples (i.e., people from two or more different places or backgrounds). The results indicate whether there is a significant difference between the samples in how they respond.

## Research Method

Explain how you tested your hypothesis in the Method section of your paper. For example, you might have hypothesized that women would be more likely than men to be in favor of raising the age for driving and you will analyze the data with a Chi-square design.

Describe your participants and their general characteristics (for example, ages, gender and race) and any characteristic important for your study (for example, whether they have drivers licenses).

Describe your research design in enough detail so that someone reading your paper can replicate it. Clarify the categories you use in your Chi-square analysis (for example, males and females; in favor or not in favor).

Write the procedure, summarizing each step in the execution of your research and what you did and why.

## Analyze the Data

Enter your data into the computer program.

Analyze your data using Statistical Package for the Social Sciences (SPSS) or another statistical package which does a Chi-Square test.

Review the output from your analysis and locate the important values.

## Write Results Section

Review the output from your data analysis and locate the degrees of freedom (df ). The df is the number of categories minus 1. If you have two categories, such as males and females, the df is 1.

Locate the numerical value of the test statistic, the Chi-square, on the output. In most outputs, it is listed under Value. In this case, let’s assume the value is 18.19

Find the probability by looking under the Significance (Sig.) on the output. Significance is the probability the results are due to your predictor variable (gender of participant, male or female) and not to chance. Let’s say the probability is less than .05.

Look for the number (N) of valid cases on the output. Let's say our number of valid cases is 90. Write the letters that refer to statistic in italics. Write Chi-square as follows: χ2

Report the results in this way: χ2 (1, N = 90) = 18.19, p < .05 for your APA paper. Within the parentheses, the first number is 1 for the degrees of freedom, N = 90 and means there were 90 valid cases, after the equal sign is the test statistic, 18.19, followed by a comma and then the probability (p) value of less than .05. The p should be in italics.

### Tip

It is best to write the method before or while you are doing the study while the details are fresh in your mind.

Write out what should be done in the study so that anyone reading it could run the experiment.