I just published a new interactive visualization in my series of basic statistical concepts and techniques. This time I am trying to show how the t-distribution and the normal distribution differs, and how they become very similar for larger sample …
Meta-analyses are often accompanied by two popular forms of data visualization: forest plots and funnel plots. In this post, I’ll show how quick-and-dirty forest and funnel plots can be created with the metafor package. After, I’ll show how we can …
ggplot2, as I’ve already made clear, is one of my favourite packages for R. And since that original post about ggplot2 remains one of my most frequently visited, I thought I would proceed with starting a series of posts called “Make It Pretty”, all …
With this post, I’m going to be showing how you can use the psych package in conjunction with ggplot2 in order to create a prettier scree plot with parallel analysis–a very useful visualization when conducting exploratory factor analysis.
Much has been said about significance testing – most of it negative. Methodologists constantly point out that researchers misinterpret p-values. Some say that it is at best a meaningless exercise and at worst an impediment to scientific discoveries. …
I often get asked how to fit different multilevel models (or individual growth models, hierarchical linear models or linear mixed-models, etc.) in R. In this guide I have compiled some of the more common and/or useful models (at least common in …