Graziano and Raulin (8th ed)Graziano & Raulin
Research Methods (8th edition)

Analysis of Variance

We set up a one-way ANOVA for the data shown in Table 10.1 of the text. These data were from our hypothetical study of typing speed and room temperature. You can enter these data yourself or download the file from this website

The key to this analysis is to remember that each participant's data appears on a different line and that there must be a variable that defines which group the subject was in. In our data file, there were 48 lines of data and two variables. The Group variable was coded 55, 60, 65, 70, 75, and 80 for the various temperatures that define the groups. The speed variable was the typing speed for each subject. This screen shows part of the final data file.

To run a one-way ANOVA, select the Analyze menu, the Compare Means submenu, and the One-Way ANOVA option, which opens this box. Move the typing variable to the Dependent List box and the group variable to the Factor box as shown in this screen. Click on OK to run the analysis, which will give you the results shown on this screen.

Note that this screen does give the ANOVA summary table, but it does not give the means and other descriptive statistics that would be needed to interpret the F-ratio. To compute both the F-ratio and the descriptive statistics, you should click on the Options button when setting up the analysis, which will give you this screen. Click on Descriptives, click the continue button, and then click on OK to run the analysis. Now SPSS will run both the one-way ANOVA and the descriptive statistics for each group, which is displayed on this screen.

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.

Running a One-Way ANOVA