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 student through them. A student 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.

swirlify is a separate R package that provides a comprehensive toolbox for swirl instructors. Content is authored in YAML using the handy tools described 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, main() to return to the main menu, 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, you can install and run the development version of swirl using the devtools package:

install.packages("devtools")
devtools::install_github("swirldev/swirl", ref = "dev")
library(swirl)
swirl()

If you'd like to get involved, please fork this repository and submit a pull request with your proposed changes. We're happy to chat if you have any questions about the source code.

Instructors around the world are using swirl in their classrooms. We think this is awesome. If you're an instructor, please feel free to do the same -- free of charge. While your students may be paying to take your course or attend your institution, we simply ask that you don't charge people directly for the use of our software or instructional content.

If you are not sure about a particular use case, don't hesitate to send us an email at [email protected].