[Cookie Cats](https://www.facebook.com/cookiecatsgame) is a hugely popular mobile puzzle game developed by [Tactile Entertainment](http://tactile.dk). It's a classic "connect three" style puzzle game where the player must connect tiles of the same color in order to clear the board and win the level. It also features singing cats. We're not kidding! As players progress through the game they will encounter gates that force them to wait some time before they can progress or make an in-app purchase. In this project, we will analyze the result of an A/B test where the first gate in Cookie Cats was moved from level 30 to level 40. In particular, we will analyze the impact on player _retention_. To complete this project, you should be comfortable working with pandas DataFrames and with using the pandas plot method. You should also have some understanding of hypothesis testing and bootstrap analysis.
- 1Of cats and cookies
- 2The AB-test data
- 3The distribution of game rounds
- 4Overall 1-day retention
- 51-day retention by AB-group
- 6Should we be confident in the difference?
- 7Zooming in on the difference
- 8The probability of a difference
- 97-day retention by AB-group
- 10Bootstrapping the difference again
- 11The conclusion
Data Science Lead at castle.io
Data Scientist at Tactile Entertainment
Brett Romero is a Data Scientist at Tactile Entertainment. He has previously worked for a range of organisations, including the United Nations Development Programme, Deloitte, and the Australian Taxation Office. You can follow him on Twitter at @mrbrettromero or read more about his work on his blog.