Best Practices for Clean Test Design

Designing a good A/B test isn’t just about what you change, it’s about how you set it up. A clean test setup ensures that your results are trustworthy, actionable, and easy to interpret.

Whether you’re optimizing a landing page, tweaking a product layout, or experimenting with messaging, these best practices will help you get the most out of every test.

Make One Clear Change at a Time

When testing two versions of a page, aim to isolate a single variable, such as a headline, hero image, CTA placement, or layout. If you change too many things at once, it can be challenging to determine which change caused the improvement (or the decline).

Set a Clear Goal

Choose a test goal that reflects the outcome you're trying to influence. Want more purchases? Use Conversion Rate. Trying to drive more people to click a button? Use Clickthrough Rate.

Select a goal that aligns with your objective, and ensure that everyone on your team is aware of what you're optimizing for.

Define Your Audience Carefully

Shogun allows you to set audience segments and traffic splits. Use these settings to ensure your test reaches the right audience, such as mobile vs. desktop users, returning customers, or visitors from a specific region.

Avoid running multiple overlapping tests on the same pages or templates, as this can muddle your data.

Let the Test Run Long Enough

Patience is key. Ending a test too early can lead to misleading conclusions. Ensure you collect sufficient data to achieve statistical significance, which typically requires waiting at least a few business cycles (such as weekends or promotions).

Avoid Major Edits During a Test

Once your test is running, avoid making large layout or content changes. Minor copy tweaks are generally safe, but more significant changes can skew your results. If you need to make a substantial update, consider pausing the test or restarting it for clean data.

Use Clear Naming and Notes

Give your tests descriptive names, e.g., “Homepage Hero CTA Test,” and take advantage of the notes feature to record your hypothesis or any mid-test observations. This helps you (and your team) stay organized and makes it easier to review results later.

Check for Device & Browser Coverage

Before launching, preview both variants across different devices and browsers to ensure everything looks as expected. Especially when testing design elements, ensure they render cleanly across various environments.

Track What You Learn

Each test should feed into your broader optimization strategy. Keep a simple record of what you tested, what the result was, and what you learned. Over time, these insights can help shape more impactful experiments.