Simple Plots

Bar and Pie Charts of Frequencies

To graphically display the relative number of various responses for a variable with a small set of possible responses, consider using a bar or pie chart. For example, suppose that your asked a set of college students how many courses they were enrolled in. A bar or pie chart could be appropriate for displaying the responses.

Step 1: Click "Analyze", highligh "Descriptive Statistics", and then click "Frequencies":

Step 2: Select the variable you would like to put into the chart, then click “Charts”:

Step 3: Select "Bar charts" or "Pie charts". If you are making a bar chart, choose to have the height of the bars represent the total number of responses or percentage of total responses:

Your chart will appear in the output file where you can edit it further:

Histograms

A histogram is used to make a bar chart of frequencies, when the variable you want represented by the heights of the bars is continuous. Since each datapoint would wind up with its own bar, you need to group them into bins

Step 1: Click "Analyze", highligh "Descriptive Statistics", and then click "Frequencies":

Step 2: Select the variable you would like to put into the chart, then click “Charts”:

Step 3: Select "Histograms", and consider superimposing a normal curve on your results

Your chart will appear in the output file:

By double clicking on the chart itself, you can modify its properties. In particular, if you dobule click on the chart, then double click on the bars in the chart, you can adjust the binsize:

Here the X-Axis is "custom", with an interval width (binsize) of 10:

Bar Plot with Errorbars

Plot the mean of one DV, for all groups defined by an IV.

Step 1: Click on “Graphs,” then highlight “Bar”:

Step 2: Select “Simple” and “Summaries for groups of cases”:

Step 3: Select “Other statistic”. Be sure your DV is in the “Variable” box inside the square brackets. The mean is the default choice for the height of the bars in your plot, but you can select something else if appropriate (e.g., the median). Put the IV into the “Category Axis” box:

Step 4: click on "Options" to add error bars. +/- 1 std. error (multiplier 1) is a good choice:

The plot will appear in the output. Double click on the plot to edit its properties so it can be more easily understood and nicer looking:

Scatterplots

A scatterplot is used to show the relationship between two continuous variables.

Step 1: Click on the “Graphs” tab on the top of SPSS window, then select “Scatter/Dot.” Click on the image of “Simple Scatter” and then click “Define":

Step 2: Choose the variables to be graphed. For this example, choose “speed” for the “Y axis” box, and “price” for the “X-axis”, then click “OK” to complete the scatterplot:

Step 3: Add a regression line to your plot. Double click on the scatter plot produced in the output screen to bring up the Chart Editor window. Click “Add fit at total” image, indicated by the green arrow:

Step 4: Select “Linear” under “Fit Method”. Be sure to check the box on the bottom of the window which says, “Attach label to line”, this will add the linear equation in your graph, then click “Apply”:

Page updated

Report abuse