If not already, R is well on its way to becoming the lingua franca of statistical analysis. It is open source, free, and extraordinarily powerful. Most importantly, more and more are being contributed to core . As of today there are at least 11,400 packages that add to the functionality of R. More packages are added daily. R is a data analysis system that is both open source and is also extensible. Open source means that the actual computer code behind all operations is available to anyone to examine and to reuse, within the constraints of the GPL 2.0. It is free software in the meaning of free speech in that everyone can use it, everyone can examine the code, everyone can distribute it, and everyone can add to it. Psychologists around the world are learning to take advantage of R for their research and this course will allow you to do so as well.

These notes and homework assignments are part of a course Psychology 314: Special Topics: An introduction to R for psychological research at Norhtwestern University.

The syllabus for this course is available at http://personality-project.org/courses/314/314.syllabus.pdf. Lecture notes and readings are available there.

Homework for week 1

Although R can be used from several different interfaces, a recommended one is to use RStudio. Thus, the homework for the first week will be download R and RStudio and practice using Markdown and some very baby steps in R.

Instructions for downloading R and RStudio

First, download R

R is hosted on mirror servers around the world. One of the most convenient ones is probably the one hosted by Rstudio in (on) the cloud:

https://cloud.r-project.org

Select your operating system, and then go to the download page

Select the most recent release (currently R-3.4.1) and click to install. Thats it!

Then, download RStudio (desktop)

Go to Rstudio.com https://www.rstudio.com/products/rstudio/download/ and select your installer (e.g. Rstudio.1.0.153-Mac )

Now open Rstudio and start using it

RStudio and RMarkdown

This is not R, but it is a convenient way to write up notes (and eventually run your R code)

Choose new file from the file menu

select R markdown as your file

A new window will open which will look like this http://personality-project.org/courses/314/example1.Rmd

Select the Knit button and you have just run your first R code, as well as making your first R markdown example.