As you crack into the world of UX design, there’s one thing you absolutely must understand and learn to practice like a pro: usability testing.
Precisely because it’s such a critical skill to master, it can be a lot to wrap your head around. What is it exactly, and how do you do it? How is it different from user testing? What are some actual methods that you can employ?
In this guide, we’ll give you everything you need to know about usability testing—the what, the why, and the how.
Here’s what we’ll cover:
- What is usability testing and why does it matter?
- Usability testing vs. user testing
- Formative vs. summative usability testing
- Attitudinal vs. behavioral research
- Five essential usability testing methods
- How to learn more about usability testing
Ready? Let’s dive in.
1. What is usability testing and why does it matter?
Simply put, usability testing is the process of discovering ways to improve your product by observing users as they engage with the product itself (or a prototype of the product). It’s a UX research method specifically trained on—you guessed it—the usability of your products. And what is usability? Usability is a measure of how easily users can accomplish a given task with your product.
Usability testing, when executed well, uncovers pain points in the user journey and highlights barriers to good usability. It will also help you learn about your users’ behaviors and preferences as these relate to your product, and to discover opportunities to design for needs that you may have overlooked.
You can conduct usability testing at any point in the design process when you’ve turned initial ideas into design solutions, but the earlier the better. Test early and test often! You can conduct some kind of usability testing with low- and high- fidelity prototypes alike—and testing should continue after you’ve got a live, out-in-the-world product.
2. Usability testing vs. user testing
Though they sound similar and share a somewhat similar end goal, usability testing and user testing are two different things. We’ll look at the differences in a moment, but first, here’s what they have in common:
- Both share the end goal of creating a design solution to meet real user needs
- Both take the time to observe and listen to the user to hear from them what needs/pain points they experience
- Both look for feasible ways of meeting those needs or addressing those pain points
User testing essentially asks if this particular kind of user would want this particular kind of product—or what kind of product would benefit them in the first place. It is entirely user-focused.
Usability testing, on the other hand, is more product-focused and looks at users’ needs in the context of an existing product (even if that product is still in prototype stages of development). Usability testing takes your existing product and places it in the hands of your users (or potential users) to see how the product actually works for them—how they’re able to accomplish what they need to do with the product.
3. Formative vs. summative usability testing
Alright! Now that you understand what usability testing is, and what it isn’t, let’s get into the various types of usability testing out there.
There are two broad categories of usability testing that are important to understand—formative and summative. These have to do with when you conduct the testing and what your broad objectives are—what the overarching impact the testing should have on your product.
Formative usability testing:
- Is a qualitative research process
- Happens earlier in the design, development, or iteration process
- Seeks to understand what about the product needs to be improved
- Results in qualitative findings and ideation that you can incorporate into prototypes and wireframes
Summative usability testing:
- Is a research process that’s more quantitative in nature
- Happens later in the design, development, or iteration process
- Seeks to understand whether the solutions you are implementing (or have implemented) are effective
- Results in quantitative findings that can help determine broad areas for improvement or specific areas to fine-tune (this can go hand in hand with competitive analysis)
4. Attitudinal vs. behavioral research
Alongside the timing and purpose of the testing (formative vs. summative), it’s important to understand two broad categories that your research (both your objectives and your findings) will fall into: behavioral and attitudinal.
Attitudinal research is all about what people say—what they think and communicate about your product and how it works. Behavioral research focuses on what people do—how they actually do interact with your product and the feelings that surface as a result.
What people say and what people do are often two very different things. These two categories help define those differences, choose our testing methods more intentionally, and categorize our findings more effectively.
5. Five essential usability testing methods
Some usability testing methods are geared more towards uncovering either behavioral or attitudinal findings; but many have the potential to result in both.
Of the methods you’ll learn about in this section, performance testing has the greatest potential for targeting both—and will perhaps require the greatest amount of thoughtfulness regarding how you approach it. Naturally, then, we’ll spend a little more time on that method than the other four, though that in no way diminishes their usefulness! Here are the methods we’ll cover:
These are merely five common and/or interesting methods—it is not a comprehensive list of every method you can use to get inside the hearts and minds of your users. But it’s a place to start. So here we go!
In performance testing, you sit down with a user and give them a task (or set of tasks) to complete with the product. This is often a combination of methods and approaches that will allow you to interview users, see how they use your product, and find out how they feel about the experience afterward. Depending on your approach, you’ll observe them, take notes, and/or ask usability testing questions before, after, or along the way.
Performance testing is by far the most talked-about form of usability testing—especially as it’s often combined with other methods. Performance testing is what most commonly comes to mind in discussions of usability testing as a whole, and it’s what many UX design certification programs focus on—because it’s so broadly useful and adaptive.
While there’s no one right way to conduct performance testing, there are a number of approaches and combinations of methods you can use, and you’ll want to be intentional about it.
It’s a method that you can adapt to your objectives—so make sure you do! Ask yourself what kind of attitudinal or behavioral findings you’re really looking for, how much time you’ll have for each testing session, and what methods or approaches will help you reach your objectives most efficiently.
Performance testing is often combined with user interviews. For a quick guide on how to ask great questions during this part of a testing session, watch this video:
Even if you choose not to combine performance testing with user interviews, good performance testing will still involve some degree of questioning and moderating. Performance testing typically results in a pretty massive chunk of qualitative insights, so you’ll need to devote a fair amount of intention and planning before you jump in.
Maximize the usefulness of your research by being thoughtful about the task(s) you assign and what approach you take to moderating the sessions. As your test participants go about the task(s) you assign, you’ll watch, take notes, and ask questions either during or after the test—depending on your approach.
Four approaches to performance testing
There are four ways you can go about moderating a performance test, and it’s worth understanding and choosing your approach (or combination of approaches) carefully and intentionally. As you choose, take time to consider:
- How much guidance the participant will actually need
- How intently participants will need to focus
- How guidance or prompting from you might affect results or observations
With these things in mind, let’s look at the four approaches.
Concurrent Think Aloud (CTA)
With this approach, you’ll encourage participants to externalize their thought process—to think out loud. Your job during the session will be to keep them talking through what they’re looking for, what they’re doing and why, and what they think about the results of their actions.
A CTA approach often uncovers a lot of nuanced details in the user journey, but if your objectives include anything related to the accuracy or time for task completion, you might be better off with a Retrospective Think Aloud.
Retrospective Think Aloud (RTA)
Here, you’ll allow participants to complete their tasks and recount the journey afterward. They can complete tasks in a more realistic time frame and degree of accuracy, though there will certainly be nuanced details of participants’ thoughts and feelings you’ll miss out on.
Concurrent Probing (CP)
With Concurrent Probing, you ask participants about their experience as they’re having it. You prompt them for details on their expectations, reasons for particular actions, and feeling about results.
This approach can be distracting, but used in combination with CTA, you can allow participants to complete the tasks and prompt only when you see a particularly interesting aspect of their experience, and you’d like to know more. Again, if accuracy and timing are critical objectives, you might be better off with Retrospective Probing.
Retrospective Probing (RP)
If you note that a participant says or does something interesting as they complete their task(s), you can note it and ask them about it later—this is Retrospective Probing. This is an approach very often combined with CTA or RTA to ensure that you’re not missing out on those nuanced details of their experience without distracting them from actually completing the task.
Whew! There’s your quick overview of performance testing. To learn more about it, read to the final section of this article: How to learn more about usability testing.
With this under our belts, let’s move on to our other four essential usability testing methods.
Card sorting is a way of testing the usability of your information architecture. You give users blank cards (open card sorting) or cards labeled with the names and short descriptions of the main items/sections of the product (closed card sorting), then ask them to sort the cards into piles according to which items seem to go best together. You can go even further by asking them to sort the cards into larger groups and to name the groups or piles.
Rather than structuring your site or app according to your understanding of the product, card sorting allows the information architecture to mirror the way your users are thinking.
This is a great technique to employ very early in the design process as it is inexpensive and will save the time and expense of making structural adjustments later in the process. And there’s no technology required! If you want to conduct it remotely, though, there are tools like OptimalSort that do this effectively.
For more on how to conduct card sorting, watch this video:
Tree testing is a great follow up to card sorting, but it can be conducted on its own as well. In tree testing, you create a visual information hierarchy (or “tree) and ask users to complete a task using the tree. For example, you might ask users, “You want to accomplish X with this product. Where do you go to do that?” Then you observe how easily users are able to find what they’re looking for.
This is another great technique to employ early in the design process. It can be conducted with paper prototypes or spreadsheets, but you can also use tools such as TreeJack to accomplish this digitally and remotely.
In the 5-second test, you expose your users to one portion of your product (one screen, probably the top half of it) for five seconds and then interview them to see what they took away regarding:
- The product/page’s purpose and main features or elements
- The intended audience and trustworthiness of the brand
- Their impression of the usability and design of the product
You can conduct this kind of testing in person rather simply, or remotely with tools like UsabilityHub.
This one may seem somewhat new, but it’s been around for a while–though the tools and technology around it have evolved. Eye tracking on its own isn’t enough to determine usability, but it’s a great compliment to your other usability testing measures.
In eye tracking you literally track where most users’ eyes land on the screen you’re designing. The reason this is important is that you want to make sure that the elements users’ eyes are drawn to are the ones that communicate the most important information. This is a difficult one to conduct in any kind of analog fashion, but there are a lot of tools out there that make it simple—CrazyEgg and HotJar are both great places to start.
6. How to learn more about usability testing
There you have it: your 15-minute overview of the what, why, and how of usability testing. But don’t stop here! Usability testing and UX research as a whole have a deeply humanizing impact on the design process. It’s a fascinating field to discover and the result of this kind of work has the power of keeping companies, design teams, and even the lone designer accountable to what matters most: the needs of the end user.
If you’d like to learn more about usability testing and UX research, take the free UX Research for Beginners Course with CareerFoundry. This tutorial is jam-packed with information that will give you a deeper understanding of the value of this kind of testing as well as a number of other UX research methods.
You can also enroll in a UX design course or bootcamp to get a comprehensive understanding of the entire UX design process (to which usability testing and UX research are an integral part). For guidance on the best programs, check out our list of the 10 best UX design certification programs. And if you’ve already started your learning process, and you’re thinking about the job hunt, here are the top 5 UX research interview questions to be ready for.
For further reading about usability testing and UX research, check out these other articles: