Small multiples are an array of graphs, on the same scale, grouped together in a row or grid. Small multiples are often used to simplify a data display. For example, when one needs to show 3 variables, a common mistake would be to create a 3D graph, which is often difficult to interpret. A better option would be to create a separate graph for each category of Variable A, which is composed of a data display for Variables B and C. The graphs themselves can take any form, such as bar graphs, line graphs, or even pie charts.
The key is really that the tiny graphs are all on the same scale, meaning their y-axis all have the same maximum and minimum values. Doing so allows a viewer to compare the mini graphs to one another.
Gender comparison by location of program
In this example, gender is graphed by location of program.
Source: Stephanie Evergreen
Advice for CHOOSING this option (tips and traps)
Choose small multiples when a single graph is too cluttered or complicated because too many variables need to be displayed. Don’t use this option if the scales would have to be altered.
Advice for USING this option (tips and traps)
Because the graphs are tiny, they need to be very simplified. Eliminate gridlines, tickmarks, and any other clutter that isn’t necessary. In terms of labeling, you can usually get away with labeling the left most graph in the series and then skip labeling the rest. If possible, order the array of tiny graphs from greatest to least on one category.
How to make a small multiples bar chart in Excel: See how several evaluators made small multiples graphs right inside Excel.
Other ways to compare sets of values
Illustrating the main features of the distribution of a data set in a clear way.
Presenting a frequency distribution of quantitative data in a graphical way.
Providing a way to communicate complicated data sets quickly and easily.
Using a target line to show progress to date, often with levels of performance graphed in the background.
Deviation bar graph
Aligning two bar graphs along their spine to compare the shape of their data sets.
Plotting two or more dots on a single line for each category being compared.
Tufte, E. (1983). The visual display of quantitative information. Cheshire, CN: Graphics Press.
Cleveland, W. (1993). Visualizing data. Summit, NJ: Hobart Press.