13.1 Begin with the comparison

Chart selection begins with what the audience must compare, not with a software menu.

Communication need	Often useful
One or two important values	Directly labelled text
Exact lookup across several values	Table
Category comparison	Bar chart
Change over time	Line chart
Numeric relationship	Scatterplot
Distribution	Histogram, density plot, boxplot, or dot plot
Composition	Stacked bar or well-labelled table
Actual versus target	Bullet chart, dot plot, or direct comparison
Geographic pattern	Map when location is analytically meaningful

The chart type is only the beginning. Scale, ordering, labels, units, colour, annotations, and surrounding text determine whether the comparison is clear.