Roughly replicating Erica's plot

jitterbox.R

library(ggplot2)

# random data
set.seed(5)
my_data <- data.frame(y = rnorm(15*5, mean=0, sd=2) + 3,
                      x = rep(letters[1:5], each=5))

# plot: jittered points + boxplot overlay
ggplot(my_data, aes(x=x, y=y)) +
  geom_jitter(aes(color=x, shape=x), width = 0.2) +
  geom_boxplot(fill=NA, size=0.2, outlier.shape = NA) +
  geom_hline(yintercept=0.5, linetype='dotted', color='red') +
  theme_classic() +
  theme(legend.position = 'none')