bar

One bar per category, all starting from the same baseline, so length stands for quantity and your eye compares lengths without doing arithmetic. It is the safest thing in the family because it has one job. The baseline has to be zero, since a bar that starts somewhere else is no longer a picture of the amount, only of the difference.

One bar per category, all starting from the same baseline, so length stands for quantity and your eye compares lengths without doing arithmetic. It is the safest thing in the family because it has one job. The baseline has to be zero, since a bar that starts somewhere else is no longer a picture of the amount, only of the difference.

Example

Best when the categories are separate things and the question is which is bigger and by how much.