Usability vs. A/B testing – which one should you use?

These days, I see a lot of people arguing over the type of testing procedures they should follow – Usability testing or A/B testing. Honestly, I find this argument quite vague. In fact, it’s not an argument at all, because, they serve completely different purposes.  We need to clearly understand which one is required when.  Let’s begin by diving into what is what and when you should go for them.

A/B Testing is what you should perform when you have two different designs (A and B), both having certain benefits, but you need to know which one has an edge over the other, or which one has a higher conversion rate.  Let’s put it this way – If you are looking for answers to questions like “Which design results in the most click-throughs by users?” or “Which design layout results in more sales?” or “Which e-mail campaign performs better?”, etc., an A/B Test is what you should go for.  A/B Testing is an effective way of testing how certain design changes (small or big) in the existing product can produce an impact on your returns.  The main advantage of performing such a test is that you can compare between two versions of the same product where the difference in design elements can be as nominal as the color of a particular CTA button or as massive as being completely different from each other.

On the other hand, if you’re looking for answers to questions like “Can users successfully complete the given task?” or “Is the navigation smooth as butter?” or “Do certain elements distract the user from their end goal?” –  Basically anything related to ease of use; Usability Testing is what you should go for.  Unlike A/B Testing, Usability Testing provides insights into user performance metrics rather than establishing the fact which design (A or B) is better.  The coolest thing about usability testing is that you can perform it on designs having any degree of fidelity – ranging from wireframes to high fidelity mockups, or even the actual finished product.  It’s completely up to you.

A/B Testing is quantitative in nature, i.e., it focuses on the “How Many”, whereas Usability Testing is qualitative in nature, i.e., it focuses on the ‘Why’.

While Usability Testing may require you to recruit participants, script your tasks and questions, analyze and make design recommendations based on your findings, A/B Testing requires no such efforts. A/B Testing allows you test your designs with real time traffic.  This sort of a test is performed on a live site, where an equal percentage of people/users are directed towards either designs and the number of click throughs and successful conversions from each design are recorded.  The results are then analyzed to determine which design trumps over the other.

Concluding, I’d like to say that it is very important to understand what type of test is required when.  Not knowing would result in costing you a lot of money, time and effort.  It is often recommended to pair one up with the other.  Why? Well, the benefits have no limits.  You can conduct usability tests to collect inputs (qualitative in nature) from the users and use A/B Tests to get insights into what can your possible design alternatives be or which alternative performs the best.  Conducting a Usability Test also ensures that there is no guess work involved in designing each of the design alternatives, and hence the designs tend to be bulletproof.

Arijit Banerjee is a UI & UX Enthusiast.  Although a power systems engineer by education, he has always found himself inclined toward the world of UX.  He has been associated with several firms and has helped define experiences across a wide range of products.  Apart from that, he’s a terrible singer, a dog lover, and an out and out foodie with decent culinary skills.  You can visit his website or follow him on Twitter.