Exercise 1: Getting Started with SPSS
This book takes you through the basic operations of SPSS with some dummy data.
5. Creating boxplots
Now let’s visualise the difference between adiposity in the two age groups. Go to Graphs > Chart Builder.
In the Choose from: menu, click on Boxplot. Drag the first image in the middle lower pane into the upper pane.
Now drag ADIPOSITY from the upper left pane into the field on the y-axis (vertical axis) of the boxplot. Drag 1 = under 40, 2 = 40-plus into the x-axis (horizontal) of the boxplot.
Click OK. Check the output viewer for the results.
In a boxplot, the width of the box does not mean anything (usually).
The thick line in the middle is the median. The top and bottom box lines show the first and third quartiles. The whiskers show the maximum and minimum values, with the exceptions of outliers (circles) and extremes (asterisks). Outliers are at least 1.5 box lengths from the median and extremes are at least three box lengths from the median. The case numbers are given for outliers and extremes so you can identify them from the data viewer.
Do you think there is a difference between age groups?
Double-click on the boxplot in the output viewer and the Chart Editor will appear. Click on individual elements in the editor to alter their properties. Explore the tabs in the Properties menu and change settings to see what happens. When you are happy with the look of your boxplot, close the editor. Go back to some of the histograms in the output viewer and try changing their formatting.
To place images or tables from SPSS into another file format, right-click on the element in the output viewer and choose Copy if you want to paste it into – for example – Word. Choose Export and select a file type if you want to save it in a different format. Select Type: None (graphics only) for image types. You can also export tables into Excel or Word.