swirl is a platform for learning (and teaching) statistics and R simultaneously and interactively. It presents a choice of course lessons and interactively tutors a user through them. A user may be asked to watch a video, to answer a multiple-choice or fill-in-the-blanks question, or to enter a command in the R console precisely as if he or she were using R in practice. Emphasis is on the last, interacting with the R console. User responses are tested for correctness and hints are given if appropriate. Progress is automatically saved so that a user may quit at any time and later resume without losing work.
swirl leans heavily on exercising a student's use of the R console. A callback mechanism, suggested and first demonstrated for the purpose by Hadley Wickham, is used to capture student input and to provide immediate feedback relevant to the course material at hand.
Course authoring is possible in a variety of formats including R Markdown, YAML, and CSV. Documentation for authoring content in R Markdown can be found on the Instructors page of our website.
The program is initiated with swirl(). Functions which control swirl's behavior include bye() to quit, skip() to skip a question, play() to allow experimentation in the R console without interference from swirl, nxt() to resume interacting with swirl, and info() to display a help menu.
The easiest way to install and run swirl is by typing the following from the R console:
install.packages("swirl")
library(swirl)
swirl()
As we continue adding new features and content, we will make new versions available on CRAN as appropriate (every 1-2 months, most likely).
To access the most recent features and content, or to contribute to swirl's development, you can install and run the development version of swirl using the devtools package:
library(devtools)
install_github("swirldev/swirl")
library(swirl)
swirl()
Note: If install_github("swirldev/swirl") gives you an error, try install_github(username="swirldev", repo="swirl") instead.