Researchers face many options when designing tests. The resulting researcher degrees of freedom are often not well documented in published work but highly influential for findings. My new in-development R package rdfanaylsis provides a coding framework to systematically document and explore the researcher degrees of freedom in research designs based on observational data.
Exploratory data analysis is important, everybody knows that. With R, it is also easy. Below you will see three lines of code that allow you to interactively explore the Preston Curve, the prominent association of country level real income per capita with life expectancy.