You want to make multiple dot plots from grouped data.

To compare multiple groups, it’s possible to stack the dots along the y-axis, and group them along the x-axis, by setting binaxis="y". For this example, we’ll use the heightweight data set (Figure 6-30):

library(gcookbook) # For the data set

ggplot(heightweight, aes(x=sex, y=heightIn)) +
    geom_dotplot(binaxis="y", binwidth=.5, stackdir="center")

Figure 6-30. Dot plot of multiple groups, binning along the y-axis

Dot plots are sometimes overlaid on box plots. In these cases, it may be helpful to make the dots hollow and have the box plots not show outliers, since the outlier points will be shown as part of the dot plot (Figure 6-31):