Correlation is one of the most widely used tools in statistics. The correlation coefficient summarizes the association between two variables. In this visualization I show a scatter plot of two variables with a given correlation. The variables are …
How easy is it to change people’s minds? In 2014, a Science study suggested that a short conversation could have a lasting impact on people’s opinions about gay marriage – but left readers disappointed when it was retracted only months later, after …
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 …