Reading your Results Report - Disaggregation Graphs
Interpreting the results of the Graph - Disaggregation function
Now that you have created your disaggregation graph, it is time to interpret what it is telling you. When you created your graph, a new sheet was added to Excel containing the chart and the data for the chart. These two pieces work together; if you change the data in the data area of the sheet, the chart will also change. For example, if you change the categories (in the first column) from the numbers 1 and 2 to "male" and "female," you will have the new names defining your categories instead of numbers. Many times, this is much better!
You are provided with two options for creating a disaggregation graph - a bar chart, or an area/line chart. Bar charts are usually the best - but a line or area chart can also be useful. If you want to show changes over time (if your categories are different points in time - for example, semesters and years of high school) an area chart is very good. If you double disaggregate your data, you can use a "clustered bar chart" by selecting the bar chart option, or can use a line chart by selecting the area/line chart option. Graphs are often a matter of taste - play with it until you find one you like!
Bar Chart. A bar chart is relatively easy to interpret. The bottom of the chart (called the X Axis) contains the values of the categorical variable you selected for your disaggregation analysis. The left side of the chart (called the Y Axis) contains the Average, Sum, or Mean score of the dependent variable you selected for disaggregation analysis. (Glossary)
Area Chart. An area chart is really nothing more than a bar chart with connected lines, and no bars. OK, it's a little different, but it is interpreted precisely the same way - values on the X axis, summary score on the Y axis.
Line Chart. A line chart is an area chart without the area underneath the line filled in. If you are disaggregating multiple dependent variables, each line will represent a dependent variable. If you are double disaggregating, each line will represent a level of your second categorical variable.
To make your charts look prettier, please see the help topic associated with Modifying your graphs.