What are the best practices for multilingual A/B testing?

1 Define your goals and hypotheses

Before you start any A/B test, you need to have a clear idea of what you want to achieve and why. This is especially important for multilingual A/B testing, as you may have different goals and hypotheses for each language or region. For example, you may want to test whether changing the color of your call-to-action button increases conversions in English, but not in French. Or you may want to test whether adding a cultural reference to your headline boosts engagement in Spanish, but not in German. To define your goals and hypotheses, you need to do some research on your target audiences, their preferences, behaviors, and pain points. You also need to use data and analytics to identify areas of improvement and opportunities for growth.

2 Choose your languages and segments

Once you have your goals and hypotheses, you need to decide which languages and segments you want to test. You may not need to test all the languages or regions that you support, as some may have similar results or low traffic. You also need to consider the cost and time of creating and translating the variations for each language. To choose your languages and segments, you need to prioritize based on your business objectives, your resources, and your potential impact. You also need to use a reliable and consistent method of detecting and targeting your users' languages, such as browser settings, location, or user preferences.

3 Create and translate your variations

The next step is to create and translate your variations for each language and segment. You need to make sure that your variations are relevant, clear, and consistent across languages. You also need to avoid common translation mistakes, such as literal translations, cultural mismatches, grammar errors, or missing context. To create and translate your variations, you need to use a professional and native translator, or a high-quality translation tool. You also need to use a multilingual A/B testing platform or tool that allows you to create and manage your variations in different languages easily and accurately.

4 Run and monitor your tests

After you have created and translated your variations, you need to run and monitor your tests. You need to make sure that your tests are valid, reliable, and ethical. You also need to avoid common testing errors, such as testing too many variables, running tests for too long or too short, or stopping tests prematurely. To run and monitor your tests, you need to use a statistical method or tool that calculates the sample size, duration, and significance of your tests. You also need to use a dashboard or tool that tracks and displays the performance of your variations in different languages and segments.

5 Analyze and apply your results

The final step is to analyze and apply your results. You need to make sure that you interpret and communicate your results correctly and effectively. You also need to avoid common analysis mistakes, such as ignoring the context, the outliers, or the confounding factors. To analyze and apply your results, you need to use a data visualization or reporting tool that shows the impact of your variations on your key metrics and goals. You also need to use a feedback or optimization tool that helps you implement and iterate on your winning variations in different languages and segments.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?