A/B Buddy
Sample Size & Power Calculator
About
This app helps you design A/B experiments by calculating the precise number of participants needed for statistically valid results. It uses power analysis to determine the optimal sample size, ensuring your experiment is neither too short nor too long.
What's New in A/B Buddy
1.1.0
April 14, 2020
• Full support for Dark Mode • A/B Buddy now requires iOS 13 or later
In-App Purchases
$8.99
Pro Features
Set statistical power and significance level
FAQ
What is A/B Buddy used for?
A/B Buddy is a sample-size calculator designed to help you determine the exact number of participants needed for your A/B experiments. This ensures your results are scientifically valid and that you can detect statistically significant differences between groups.
How does A/B Buddy calculate sample size?
It uses a power-analysis formula. You input your current conversion rate and the desired minimum detectable effect (e.g., a 20% lift), and the app calculates the required number of subjects or users.
Is my data private when using A/B Buddy?
Yes, your data remains 100% private. The app stores all calculation information within the URL fragment, which is then shared. No data is transmitted to any servers.
What are the default statistical thresholds in A/B Buddy?
By default, A/B Buddy uses a 5% significance level (false-positive rate) and an 80% power level (ability to detect the minimum detectable effect). These are common thresholds for statistical analysis.
Can I adjust the statistical thresholds in A/B Buddy?
Yes, advanced users can adjust these values by unlocking the Pro Features through an in-app purchase. However, the default settings are adequate for most users' needs.
Does A/B Buddy have ads?
No, A/B Buddy does not contain advertisements. The app is free to use, with an optional in-app purchase for advanced features.
What devices is A/B Buddy compatible with?
A/B Buddy is compatible with iPhones, iPads, and iPods. It is designed for iOS devices.
How often is A/B Buddy updated?
The latest version, 1.1.0, was released on April 14, 2020. The app was initially released on January 15, 2019, suggesting periodic updates for improvements and bug fixes.
