| graphical element  | `geom` used             | argument for further modification |
| :----------------- | :---------------------- | :-------------------------------- |
| bars               | `ggplot2::geom_bar()`   | `NA`                              |
| descriptive labels | `ggplot2::geom_label()` | `label.args`                      |
| sample size labels | `ggplot2::geom_text()`  | `sample.size.label.args`          |
