These are materials from an online workshop introducing R to the Ohio Program Evaluators’ Group. The focus was on the fundamentals of R & Rstudio, importing and cleaning data, frequencies and other descriptive statistics, and simple visualizations with {ggplot2}.
The cohort had already received instructions on installing R & RStudio so you won’t find that here. Instead we jumped right into reading and cleaning data, and then some common data chores such as calculating quantities of interest, data summaries, binning data, and saving data.
ggplot2ggplot2 is one of the more popular R packages for data visualization and hence is the package I walked participants through. It can do a lot but we focused on the very basics, the type of visualizations one may need for program evaluation. In particular, we looked at bar-charts, histograms, box-plots, scatter-plots, line-charts, and closed with a simple map or two.
Participants completed a short survey in advance of the workshop. In that survey, a number of respondents said they were interested in learning how to conduct the usual battery of statistical tests in the course of evaluating a program. This is a quick overview of the necessary commands and, where feasible, tests for assumptions underlying the tests, etc.