Calculating and visualizing error bars for within-subjects designs

What this post is about Creating data Creating a violin plot (with wrong errors bars) Creating another plot (with error bars that’re still wrong) The last plot (this time correct) What this post is about Personally, I find violin plots with error bars a great way to present repeated-measures data from experiments, as they show the data distribution as well as the uncertainty surrounding the mean. However, there is some confusion (at least for me) about how to correctly calculate error bars for within-subjects designs.