Small multiples are a series of small visualizations that allow users to simply and quickly interpret changes across each visualization.
Small multiples are best used when representing simple visualizations that include a small number of dimensions. Because small multiples are used to compare differences across visualizations, the visualization type used and the data compared should be consistent across the entire series of visualizations.
Small multiples can be used with bar charts, histograms, line graphs, pie charts, and choropleth maps. Other visualization types are often too complex to be rendered at a small size, resulting in changes across visualizations becoming lost.
Quarterly Population Rates by Regional Office
Why it’s Only Acceptable
Choosing the right data visualization depends on a number of factors, one of which is intent. In this case, the intent of this visualization is to visualize quarterly population rates by regional office. A stacked bar chart excels at showing broader changes in data across several categories, but when it comes to understanding granular changes in data, it requires more time and energy for users to understand.
Quarterly Population Rates for Atlanta
Quarterly Population Rates for Chicago
Quarterly Population Rates for Denver
Quarterly Population Rates for New York
Why it’s Preferred
In this preferred example, each category of data is represented as its own horizontal bar chart. Although this approach takes up more space, it also allows for easier comparisons of values across each data category.
Order graphs in some logical manner, e.g. time.
If it makes sense for the type of chart used and if space allows, align the charts in a single row or column so that the viewer can make comparisons along a single baseline.
Don’t use any scale bars not mentioned in this guidance unless you are an expert cartographer.