Creating a combination chart to display respondent means as points and bars

This worksheet explains how to use a combination chart to compare the means of groups of respondents in a satisfaction survey with the mean responses of all respondents.

The worksheet uses the data provided in the snCrocodile survey supplied with Snap to display the average satisfaction for men and women at the Crocodile cafe against the average satisfaction of all respondents. To make it obvious which the reference values are, they will be displayed as bars, whereas the individual means for men and women will be displayed as points.

Background

The snCrocodile survey includes questions to classify respondents by age and gender. These allow you to use this information to target marketing or to focus on where your service could be improved.

While you may sometimes wish to compare the groups of respondents directly, you may also wish to see how various groups of respondents have answered when compared to a baseline.

To create the average respondent, you create a variable that is set to true for all respondents, and you can then analyse the satisfaction of all respondents against the satisfaction of any other groups that you define.

To make this comparison clear, you can use a combination chart so that the baseline values are displayed in a different format to the selected groups. In this example, a bar chart is used for the baseline values, and line charts are used for the group values. The line charts can be set up to have different symbols for the datapoints of each group.

Summary of steps

Step 1: Add the derived variable to your survey
Step 2: Create a combined chart
Step 3: Style your chart to display points and bars
Step 4: Set up the datapoint markers for your chart

Step 1: Adding the derived variable to your survey

  1. Open the snCrocodile survey in Snap.
  2. Click VariablesButton to open the Variables window.
  3. Click Plus to create a new variable.
  4. Set the Label to All Respondents.
  5. Set Type to Derived and Response to Single.
  6. Click in the Code Label area and set the it to All.
  7. Set Values for that code label to True.

    Create derived variable All in Snap 9

  8. Click Save button to save the new variable. By default it is given a name of V1.

Step 2: Creating a combined chart

  1. Click Results Definition button to open the Results Definition dialog.
  2. Change the Chart style to Bar 2D.
  3. Set the Analysis field to Q6a~Q6e. This includes all the satisfaction questions (you can check what they are in the open Variables window).
  4. Set the Break field to V1: Q10. (V1 is your newly created derived variable, Q10 is the gender question).
  5. Set the Calculate field to Means & Differences.
  6. Check the Transpose box under Options.
    Results Definition / check Transpose box
  7. Click [OK]. The chart window opens, displaying the defined bar chart.
    Chart window / displaying bar chart

Step 3: Styling your chart to display points and bars

  1. Open the chart designer by clicking Style mode button on the chart toolbar. The chart designer dialog appears.
  2. Highlight Chart in the left-hand pane if it not already selected. This is the section of the chart designer that defines the overall look of the chart.
  3. Ensure that the 2D radio button is selected and click Combination in the list of chart types.
  4. Click [Apply] to use these settings without closing the chart designer window.
  5. Select Series in the left-hand pane. This is the section of the chart designer dialog that deals with the display of the break and analysis data. This is where you specify that in the combination chart, you wish to display the All information as bars, and the data split by gender as lines.
    • Click All Series box and check that Bar is selected in the Display As box.
    • Select Male in the Series box and select Line in the Display As box, then do the same for Female.

      Chart Designer dialog

    • Click [Apply] to use these settings without closing the chart designer window.
    • The visible chart should change to show a combination bar and line chart.

    Combination chart with line points hidden

  6. Unfortunately, the bars are in front of the lines, making it difficult to see them. Select Series in the left-hand pan again, and click the Order tab.
  7. Select All in the list and click the [Down] button twice to move it to behind the Male and Female displays.
  8. Click [Apply]. The chart updates to place the lines in front of the bars.

    Combination chart with lines on top

Step 4: Setting up the datapoint markers for your chart

Now you have created a combination chart, you want to mark the points that represent the data values for men and women, instead of just having them as points where the lines angle.

For simplicity, use a blue square to mark points for men, and a red circle to mark points for women.

  1. Click the cross box by Series in the left-hand pane to show the list of the variable codes in the Break.
  2. Click the cross box by Male to show the list of controls for displaying the information for the data for Male. Select Datapoint defaults. This is where you specify how the datapoints for Male will be displayed.

    Select Datapoint defaults

  3. Click the Markers tab to define the markers. (You can specify the line colour in the Fill tab.)
    • Check the Show markers box.
    • Set the Style to Star.
    • Leave the Color, Size and Pen Width as they are.
    • Click [Apply] to update the chart.
      Define the markers
  4. Display the Datapoints information for Female in the same way.
  5. Select the markers tab, show markers and set the style to Filled Circle and click [OK] to close the chart designer.Combination bar and line chart

Fine-tuning your chart

If you wish, you can make further changes to your chart. You can change the colour and style of the line, got to the Lines tab for the selected series.

Chart designer showing lines tab for male datapoints

You could even remove the lines entirely, so that the point markers are floating on their own in front of the bars.

Note that changing the line colour doesn’t change the marker colour.

You can change the colour and look of the bars by selecting Datapoints in the All series in the left-hand pane and selecting the Fill tab.

If there is a topic you would like a worksheet on, email to snapideas@snapsurveys.com