We took a look at stacked bars in Chapter 1, Taking Off with Tableau, where we noted one significant drawback: it is difficult to compare values across most categories. Except for the leftmost (or bottom-most) bars, the other bar segments have different starting points, so lengths are much more difficult to compare. It doesn't mean stacked bars should never be used, but caution should be exercised to ensure clarity of communication.
Here, we are using stacked bars to visualize the makeup of the whole. We are less concerned with visually comparing across categories and more concerned with seeing the parts that make up a category.
For example, at the hospital, we might want to know what the patient population looks like within ...
