m38 problem set STATISTICS

Presenting Data Graphically

 

The following tells you how to construct various graphs and the types of graphs that are appropriate for different levels of measurement.

 

For our example, let’s construct a bar chart (bar charts may be used for nominal and ordinal variables) for our variable ‘happy’.

 

Go to Graphs, Legacy Dialogues, select Bar and then select the type (if you have only one variable, choose Simple) then Define.  This box gives you a number if things to determine. Select your variable by highlighting it and clicking on the Category Axis arrow. (this will put your variable on the “x” axis of the graph. You will determine the format of the “y” axis by selecting whether you want the chart to reflect the number or percentages of cases. Let’s decide that we want our graph to be based on numbers, not percentages (that is the default). Your screen should look like this:

 

If you want to creat a title for your graph, click on the Title button and then Continue. 

Your output will look like this:

You can use the following directions to create a number of different types of graphs:

 

Construction of Pie Charts: (nominal, ordinal)

 

Go to Graphs, Pie. You will select your variable and click the “Define Slices by” arrow. Again, you will determine whether you want your Pie slice to be measured by N or a percentage. Once again, click on the Options button to make sure that missing vales are removed. You can also use Titles for pie charts as well.

 

Constructing Histograms: (interval, ratio)

 

Histograms have an x axis (variable categories) and a y axis (frequency or percentage). However, unlike bar charts, histograms have contiguous bars. Go to Graphs, Histogram and enter the variable. You don’t have to worry about eliminating missing data for histograms, SPSS does that automatically.

 

Constructing Line Charts: (interval, ratio)

 

Go to Graphs, Line, select your variable and determine if your y axis will be frequency or percentage. You must check that missing data is eliminated here in the Options button.

 

Editing your charts:

 

If you want to change colors or the fill for your chart, double click on your chart in the output viewer. You will get a chart editor box. You can either click on the Properties button or go to Edit and Properties to change color, background, and other aspects of your graph. 

 

 

Here is some additional information about how you may use SPSS for individual variables.