geom_tukey() in ggplot facet_wrap about ggtukey HOT 5 CLOSED

Perfect! It is working exactly how I wanted it. Thanks so much for the help, Ethan! Cheers, Mike

Thanks so much for the reply Ethan! Sorry I didn't make myself clear, let me give you an example here: Imagine that there are multiple observations (values) from three groups under three conditions. I want to plot three plots for the conditions, each plot will have the values by groups. And I want to test if the values are different between groups in each plot. So I did: ggplot(data, aes(x=group, y=values))+ boxplot()+ facet_grid(~condition)+ geom_tukey() Assuming the observed values by group and condition are all different from each other, we will end up with three plots, the Tukey significance letters should be: plot 1: a, b, c plot 2: a, b, c plot 3: a, b, c This is what I meant by 'reset the significance letters from one plot to another other'. However, it seems like the significance letters continued across plots: plot 1: a, b, c plot 2: d, e, f plot 3: g, h, i It would be ok if I only have 3 groups by 3 conditions. But in reality, I have 14 groups by 12 conditions. Thus, the final plots look very messy with multi-alphabet significance letters. I hope this makes my question clearer :) otherwise I can make some graph when I am back in the office tomorrow. Thanks so much for your help! Mike