how do I use cyber-dojo?

cyber-dojo is designed to be used as follows:

1. creating your new session

From the home page one person connects their laptop to a projector...
  • click
    we're in a group
  • click
    create a new session
  • click your chosen [language, tests?]
  • click your chosen [exercise?]
  • click
  • your session ID will be displayed, eg 3AF65A
  • leave it displayed so the pairs can join...(see step 2)
  • when everyone has joined, click
    to open a dashboard (see step 4)

2. joining your session

Each pair now enters the session. Each pair, from the home page...
  • click
    we're in a group
  • click
    join a session
  • type in the cyber-dojo's id, e.g.,
  • wait until your animal is displayed (eg panda)
  • click
  • each pair is now in their own test environment

3. programming inside your session

From their test environment everyone programs for a fixed amount of time e.g., 45 minutes
  • write tests, click
    to see if they fail
  • write code, click
    to see if they pass
  • each
    click creates a new traffic-light :
    • red if one or more tests failed
    • amber if the tests could not be run (eg syntax error)
    • green if all the tests passed
  • remember, cyber-dojo is not a personal development environment
  • remember, cyber-dojo is a shared learning environment
  • the aim is not to finish, the aim is to improve
  • when time is up everyone stops programming

4. reviewing your session

The dashboard (from step 1) displays all the animals and their traffic-lights...

list of donators

  • Companies.
    Schlumberger Beijing Geoscience Center have found cyber-dojo an invaluable tool for training and development of our software community and believe the project has a bright future. Thank for you contribution to our training efforts. We are delighted to sponsor the cyber-dojo project by contributing $1000.

  • Individuals.
    Olve Maudal, Mike Long, Mathieu Baron, Steve Coates, Johannes van Tonder, Santeri Vesalainen, Alexander Ottesen, Anders Schau Knatten, Mike Sutton, James Grenning, Allan Kelly, Randall White, Lucas Videla, Mark Sargent, Jason Jolly, Mark Grimes, Pedro Gimenez, Marc Kannegiesser, Oliver Baylis, Brian Porter, Jamie Toolin, Alejandro Perez Garcia, Pavol Rovensky, Wojciech Kozlowski, Dan Grassi, Juan Alday, Damian Crawford, Seb Rose, Emily Bache, Michael Coxeter, Fernando Sola Ortiz, Sean Moir, Michael Aderskog, Daniel Aquino, Emyr Williams, Clayton Hunt, Tallapaneni HariBabu, Eric Lefevre, Thomas Rytz, Robert Senkbeil, Charles Armitage, Tobias Froberg, Michael Hilton, David Whittaker, Owen Phelps, Elliot Blackburn, Robert Pitchford, Kevlin Henney, Magnus Lassi, Amitai Schlair.

  • Thank you.

frequently asked questions

Why don't you add auto refactoring?

No. Listen.
Stop trying to go faster; start trying to go slower.
Don't think about finishing; think about improving.
Think about practising as a team.
That's what cyber-dojo is built for.

Why don't you add ...?

No. Listen.
Stop trying to go faster; start trying to go slower.
Don't think about finishing; think about improving.
Think about practising as a team.
That's what cyber-dojo is built for.

cyber-dojo is not an individual development environment
cyber-dojo is a shared practice environment
cyber-dojo is a shared learning environment
cyber-dojo gently provokes; provocation encourages learning

how do I create and share a cyber-dojo customized practice session?

Suppose you want to create your own tailored starting point. For example, you might want to create a practice session where the tests are already written. Or some legacy code to practice refactoring.

Without Automation

Prepare your files in a practice session. When you think you have your files how you want them, click the [test] button. If everything is as expected make a note of...
  • the 6 character id (from the URL or the footer); suppose it is k5ZTk0
  • the last traffic light's number; in this case 10

Click on the latest (right-most) traffic light. This will switch to review/diff mode. Below the big [resume] button there is a smaller [fork] button.

Click the [fork] button. This will open a dialog box asking if you want to create a group practice session or an individual practice session.

Click the [group] button. This will open the group practice session landing page, displaying its id. In this example QLstUP is a new group practice session id which is good for one practice session only.

With Automation

The following URL will fork from the 10th traffic light of k5ZTk0, creating a brand new group practice session with its own unique id, each time it is clicked:

<a href="" target="_blank">Start a new cyber-dojo from my awesome starting point</a>


  • you can also use index=-1 in the URL to specify the latest traffic-light
  • URLs using the old format, eg forker/fork/58E4486EE2?avatar=panda&tag=10 will continue to work but are deprecated

analyzing traffic-light transitions

As I write this cyber-dojo has hosted about 15,000 practice dojos. I've written a short ruby script to extract some measurements from a sample of about 500. I looked at transitions between red, amber, and green traffic-lights:
  • red means one or more tests failed
  • amber means the tests did not run (eg syntax error)
  • green means the tests ran and all passed
The first column is average number of lines added/deleted.
The second column is colour → colour transition.
The third column is sample size.


Here's how I interpret the results:
  • If you're at red or green and you make a small change (5.39,6.01,7.52) you're likely to stay at red or green.
  • If you're at red or green and you make a large change (13.65,17.67) you're likely to transition to amber.
  • There is a big spike in the number of amberamber transitions (1462). I speculate that long sequences of these transitions are occuring after a large 13.65 greenamber or 17.67 redamber transition.
  • I think the greengreen value of 22.18 is larger than it should be because it's including renaming a file.