Dumbbell Plot
Also called: Connected Dot Plot, Dumbbell Dot Plot
Dumbbell dot plots — dot plots with two or more series of data — are an alternative to the clustered bar chart or slope chart.
A dumbbell dot plot can be used to visualize two or three different points in time, or to triangulate different viewpoints (e.g., one dot for Republicans and another dot for Democrats, or one dot for principals and another dot for teachers).