A/B testing: A designers guide

In the design world, making informed decisions is key to creating products that users love. A/B testing, also known as split testing, is one of the most powerful tools in a UX designer’s arsenal for validating ideas, improving user experiences, and achieving business goals.

What Is A/B Testing?

A/B testing is an experiment where two versions (A and B) of a design element are tested with users to determine which performs better. This could be anything from button colors to full-page layouts. Version A serves as the control, while Version B introduces a change to test its effectiveness.

Example:
Imagine you’re redesigning a homepage banner. In Version A, the button says “Learn More,” while in Version B, it says “Get Started.” A/B testing lets you compare which button drives more clicks.

Why Is A/B Testing Important?

1. Data-Driven Decisions
   No more guessing! A/B testing provides concrete data on what works and what doesn’t.
   Example: A food delivery app tested “Order Now” vs. “Start Your Order.” The latter increased conversions by 15%.
2. User-Centric Design
   Users don’t always behave as expected. Testing allows designers to align decisions with actual user behaviour.
3. Minimized Risk
   Rolling out untested changes can backfire. A/B testing ensures that only effective updates go live.
4. Continuous Improvement
   Even small tweaks can make a big difference. A/B testing enables ongoing optimisation to refine the user experience.

How Does A/B Testing Work?

1. Identify the Problem
   Pinpoint what you want to improve. Is it a low click-through rate, a high bounce rate, or poor conversion rates?
   Example: An e-commerce site notices users abandoning their carts.
2. Set a Hypothesis
   Define the change you want to test and the expected outcome.
   Hypothesis: Changing the “Add to Cart” button colour from gray to green will increase clicks.
3. Create Variants
   Design the control (A) and the variant…