How do I choose a sample size for A/B testing?

How do I choose a sample size for A/B testing?

Choosing a sample size for A/B testing involves considering your desired confidence level, the minimum detectable effect, and the variability in your data. What specific metrics are you looking to test?

I'm testing a new website layout and want to know how many visitors I need.

For website layout tests, a common approach is to aim for a 95% confidence level and a power of 80%. You can use online calculators to input your expected conversion rates and determine the sample size needed.

What if I have a small audience?

If you have a small audience, you might need to adjust your expectations for statistical significance. Consider running the test for a longer period to gather enough data or focus on larger changes that are easier to detect.

Are there any tools to help with this?

Yes, there are several tools available, such as Optimizely, VWO, and Google Analytics, that can help you calculate sample sizes and run A/B tests effectively.