Usability testing: The complete guide

A well-designed system is still considered a failure if it does not provide an intuitive and user-friendly experience. Today’s users have many options to choose from and very little tolerance for cumbersome interfaces.

If it takes too much work to learn or navigate a product, users will quickly move on to other products. As Steve Krug, author of the book Don’t Make Me Think, notes, “if you treat users badly enough and exhaust [their goodwill], there’s a good chance that they’ll leave.

But leaving isn’t the only possible negative outcome; they may just not be as eager to use your site in the future, or they may think less of your organization.”

Usability testing offers a practical approach by allowing testing of how actual users interact with the product in realistic scenarios. In this post, we’ll look at how you can use usability testing by understanding what it is, how it works, its benefits, challenges, and best practices.

What is usability testing?

Usability testing is a testing technique that involves watching real users interact with your product. You do this to identify potential problems and enhance the user experience.

It’s different from surveys, in which you prompt users on what to do. Rather, with usability testing, you observe what they actually do, making special note of any confusion they have.

Usually, a usability test involves five to eight people, including a facilitator. The facilitator assigns tasks and encourages users to speak aloud. The observer or software records their clicks, where time is lost, and their verbal comments.

Usability testing is about testing the product, not the user. The idea is that every time the user struggles or makes a mistake, it’s data that tells you what to fix.

Usability testing measures effectiveness, efficiency, and satisfaction. It’s used in development, from testing out ideas on paper before you begin coding to validating a product after it’s launched.

For these reasons, usability testing is considered the most effective way to ensure a product is designed to meet real users’ needs.

Usability testing is about testing the product, not the user.

Why is usability testing important in software development?

Below are some reasons why usability testing is important:

1. Helps you avoid creating a counterproductive product

Usability testing helps you create features that are usable, not just technically viable, for your users. There are products out there that have gone through every quality assurance process and still fail, simply because users can’t navigate them.

2. Drives business metrics

By improving ease of use, you boost conversions, reduce support calls, lower return rates, and enhance customer retention.

3. Reduces technical debt

When the interface is unusable, it incurs usability debt. This means the interface presents problems for users and creates debt that has to be paid off with tooltips, onboarding tours, FAQs, and pop-up modals.

4. Supports evidence-based practices

Focusing on usability testing gives product managers, designers, and developers a common ground of truth for creating products. It addresses real user needs instead of personal opinions.

5. Catches what automation can’t

QA and test automation only verify that the software meets its requirements.  However, testers can’t prove that the requirements are good. Usability testing is about how users interact with the software.

6. Enhances agile and continuous delivery

Usability testing is a lightweight process that three to five users can do. It is well-suited to an iterative sprint. For example, teams can test a new feature, gather feedback, and deploy an improved version within a short time.

7. Establishes goodwill with users

Users aren’t willing to put up with confusing software. Easy-to-use software builds loyalty and confidence.

How does usability testing work?

Usability testing works by placing a real user in front of your product, providing them with realistic tasks, and monitoring what happens without providing any help. Here are the steps to follow.

Step 1: Define tasks

You create three to five realistic tasks that lead up to the test objective. You can include a hint. Tasks should contain a realistic scenario. For example, imagine you bought a shirt but entered the wrong address; the goal might be to change it before the order ships.

Step 2: Recruit participants

You can identify five to eight people who you think are your target audience. You could involve coworkers and friends, but it is better to have it done by representative users.

Step 3: Run sessions

You’ll give the participants the first task and instructions. You’ll then guide them. Sessions last fifteen to thirty minutes. You’ll make observations and note verbatim quotes from your users.

Step 4: Analyze findings

At the end of each session, you’ll revisit the notes and identify patterns. A problem viewed by two or more users has high priority. A problem that completely hinders a user is a critical priority. You then rank three to five of those problems and provide concrete solutions.

After the fix is done, retest the code

Implement the high-priority fixes and run another test to confirm they were successful. This testing, fixing, and retesting is repeated until the product runs smoothly. The full cycle may take place in a single day.

What are the different types of usability testing?

Below are different types of usability testing.

1. Moderated vs. unmoderated

Moderated testing involves having a live facilitator who asks questions and probes behaviors as they happen. It offers a lot of depth, but takes a lot of time and skill.

Unmoderated testing involves the user completing tasks independently on an automated platform such as Maze or UserTesting, which captures the user’s screen and audio. It scales to hundreds of users, and it’s faster and cheaper, but it can’t react to unforeseen actions.

2. Qualitative vs. quantitative

In qualitative testing, the number of participants is five to eight, and the focus is on deliberate observation of behaviors, taking down feedback from your users, and understanding why problems occur. It’s very good at finding new problems.

Quantitative testing involves twenty or more participants and assesses metrics such as success rate, time on task, and satisfaction scores.

 

3. In-person vs. remote

In-person testing involves the facilitator being in the same room as the participant. It is suitable for hardware or gesture products.

With remote testing, you use screen sharing or specialized platforms. It allows you to conduct testing with participants from all over the world.

4. Task-based vs. exploratory

Task-based testing assigns the participants specific tasks, like “Find the return policy.” It’s the most frequent structure, and it’s best to assess effectiveness and efficiency.

Exploratory testing involves giving users a general objective. An example of a goal might be to explore the app and describe what certain features are doing. It’s helpful during initial concept testing and first impressions.

Guerrilla testing requires you to visit public areas like cafés or libraries and interact with strangers.

5. Guerrilla testing

Guerrilla testing requires you to visit public areas like cafés or libraries and interact with strangers. It’s extremely fast and cheap, and it’s ideal at an early stage for directional feedback.

The sample, however, is not representative, and the conclusions drawn should be considered hypothesis-generating. This is ideal for when you have limited resources.

6. Specialized types

As the name suggests, specialized tests are for a specific niche. For example, consider eye-tracking testing that uses hardware to capture users’ gaze. The goal with this type of test is to identify visual hierarchy problems.

Specialized testing also covers accessibility testing, which is not only useful for tracking down issues that automated tests may not find, but it also includes users with disabilities using assistive technologies such as screen-reading software.

They have very specific needs that require specialized tests.

7. Longitudinal Testing

This test involves the same users being tested multiple times over days or weeks to determine how quickly they learn and how much they remember between tests. This type is essential for products used frequently, such as a productivity application or an educational platform.

When should teams use usability testing?

Here’s a list of times when you should employ usability testing.

1. Discovery phase

To determine if users need and understand their product, teams should validate concepts early in the process through testing with basic sketches or competitor products.

Users could present a mock ad or storyboard in a concept test and ask, “What problem is this trying to resolve?” By doing this, you can avoid building a product that nobody wants.

2. Low-fidelity prototypes

Teams should conduct paper prototyping and grayscale wireframing to ensure the information architecture, navigation labels, and overall workflow. At this stage, changes take minutes. A team can draft the next menu, test it with three people for twenty minutes, and revise it.

3. High-fidelity design

This involves using polished interactive prototypes to evaluate interactions, error messages, button placement, and form design. What takes five minutes in Figma could take five days in code.

4. Before launching

Groups need to challenge the production candidate with quantitative values, like “95% of users complete checkout in less than two minutes,” amongst twenty to forty participants. The results either validate readiness or expose any significant hurdles that need to be addressed.

5. Live product testing

Teams need to test the product in a live environment with real customers. This helps identify problems that only come to light with real users. Post-launch testing uncovers issues that other users have had no trouble with.

You should conduct benchmark testing regularly, even if there has been no significant redesign.

6. Regularly and continually

You should conduct benchmark testing regularly, even if there has been no significant redesign. You’ll be aware of regression or changes in user expectations. Products change over time because of bug fixes or enhancements.

A search facility that did a great job six months ago could get confusing when developers add three features. Continuous testing catches this drift.

How does usability testing fit into QA and test automation?

Usability testing exists in parallel to QA and test automation. It’s a complementary method to address a different question.

QA and test automation ensure the software performs as specified. Usability testing ensures that real people can use that software without confusion, frustration, or error. 

Automation runs assertions in a very prescriptive script, whereas usability testing observes unpredictable human actions. They complement each other. The usability test may also identify edge cases that need to be automated by QA.

QA testing may reveal functional issues disguised as usability issues, like a poorly working JavaScript handler that causes a form to appear confusing.

Mature teams use both: product managers set criteria involving both functional requirements (automated) and usability requirements (tested with real users).

What are the 5 Es of usability?

The 5 Es of usability testing is a framework for assessing user experience beyond task completion. It also allows you to determine if a user can do something and how they feel while doing it.

The 5 Es include:

Effective

Effectiveness determines if users can successfully and completely accomplish their desired goals. If it’s not effective, all else is negated because users cannot perform what they intended.

Efficient

Efficiency measures how quickly and with how little effort users take to finish tasks. It looks at time spent on tasks, clicks, or thought load needed to achieve a desired outcome.

Engaging

The engagement is the level of pleasantness, satisfaction, and motivation that the interface provides to the user. It demonstrates how the user feels about the product and whether they would want to use it again. High engagement makes functions fun and creates loyalty.

Error tolerant

Error tolerance measures the ability to anticipate, tolerate, and recover from user errors.

A forgiving design offers clear error messages, undo options, and confirmation dialogues before destructive actions. High error tolerance limits frustration and helps users become more confident with the process, particularly in complex or high-stakes activities.

Easy to learn

This checks how quickly a first-time user can become proficient using the interface.

It highlights the initial learning curve, time to first success, or external learning support/training required. Easy-to-learn products lower onboarding costs and enable casual customers to return at unpredictable intervals.

What are the best practices for effective usability testing?

Here’s a list of best practices to help your usability testing be as productive as it can be.

1. Recruit people who are actually your target audience, not co-workers, friends, or relatives who know the product well and don’t want to offend.
2. Get a small, representative sample vs. a large, convenient sample. Small beats large every time. According to Jakob Nielsen of the Nielsen Norman Group, “five participants [find] 85% of the usability problems,” while eight users can identify almost all the major issues.
3. Implement real-world situations that provide context and motivation. For instance, think of our earlier-mentioned problem in which you purchased a shirt but entered the wrong address.
4. Don’t use jargon, technical terms, or internal feature names that users wouldn’t know.
5. Record the testing session for analysis, including the screen and the user’s voice at all times, and preferably their face. Video plays a vital role in reviewing missed information.
6. Identify the issues and prioritize them based on severity. Assign a rating based on how many users had each issue.
7. Don’t just gather data; take action based on that information. Fix the most critical problems and test with three to five new volunteers to validate the fixes.
8. Share findings with video clips. Stakeholders will subscribe to video evidence over any report.
9. Use realistic devices and conditions for testing. Never test a mobile app on a laptop. Avoid testing in a quiet laboratory when the product will be used by users on a noisy train.
10. Know when to stop. When the analysis findings are clear and actionable, stop the analysis at the top three to five issues. No analysis is better than a timely fix.

Don’t just gather data; take action based on that information.

What challenges do teams face with usability testing?

There are a number of challenges you’ll encounter as you implement usability testing.

1. Finding the target audience

The first challenge you may come up against is that finding participants who truly represent your target audience is hard and time-intensive.

Many teams forgo testing altogether because of its high no-show and cancellation rates, and the targeted B2B audience may be so elusive that no one can ever get a hold of it.

2. Small samples lack statistical confidence

Another challenge is that small samples lack statistical confidence. Your five users might find most issues, but no one can be certain that a finding applies to all users. What seems to be a problem for two users could be an issue for 20% of your audience or just those two users.

3. Artificial environments change behavior

You may also notice that artificial environments change behavior. The participants are aware that they are being monitored and thus behave differently from real users.

Labs are free from the distractions of real-world emails, calls, and time pressures. The problems that emerge may not accurately reflect the situation.

4. False positive outputs

You could find a problem that real users will never encounter (false positive), thus wasting time on unnecessary fixes.

Or else you may overlook a real problem because your five participants missed it (a false negative), leading to customer complaints that go unnoticed after the launch.

5. Moderator’s inconsistency and bias

Not only that, but you might be dealing with the moderator’s inconsistency and bias. Data quality is directly impacted by the facilitator’s skill.

Fatigued moderators cannot pick up on nuances. And results might not be comparable if they are from different moderators who moderate differently. Unlike automated testing, usability testing is not a consistent test.

6. Analysis is overwhelming

Another point to consider: analysis is overwhelming. An hour of testing results in an hour of video, pages of notes, and hundreds of data points.

Analysis typically requires two to four hours per participant and test hour. When teams are under pressure, they don’t do proper analysis, so they either fix everything or fix nothing.

7. Hard-to-test scenarios

And then there are the hard-to-test scenarios. Emergency apps can’t induce real stress. There are features that rely on months of usage that cannot be tested in one hour.

It’s these scenarios that will make teams have to deal with more uncertainty.

How can teams get started with usability testing?

This is how teams can get started with usability testing.

Start small

Avoid testing your entire product. Choose one important task, e.g., signing up, checking out, or finding a feature of the website. Conduct your initial test with three to five people not on the product team.

Use the five-user rule

You only need five users to find approximately 85% of usability problems. Avoid waiting for thirty people to be available.

So recruit five members of the community this week! Test number one is friends, family, and coworkers. Representative users will follow. The idea is to begin, not to be perfect.

Write three to five realistic tasks

Write tasks that focus on objectives and not clicks. Replace instructions like “click ‘Support,’ then ‘FAQs,’ then ‘Returns’” with “find the return policy.” Add a scenario and motive: “You just purchased a shirt, but you entered the wrong address—change it before it ships.”

Use neither internal feature names nor jargon nor any language that the users wouldn’t know. Pilot with one person before running all sessions.

No lab required

Use a quiet room, a laptop or phone, and a screen recorder such as OBS Studio or QuickTime (both are free). One person coordinates silently and doesn’t help. Another person is writing notes on what they’re observing and users’ quotes.

That’s it. It’s not a one-way mirror. No eye tracker. No specialised software. Teams have used a phone and a notebook to run excellent usability tests.

Begin each session with “I test the product, not you. There is no right or wrong. Just think out loud if you get stuck.”

Use a simple script

Begin each session with “I test the product, not you. There is no right or wrong. Just think out loud if you get stuck.” Read the first task, then go silent. If a user requests assistance, say, “What do you feel you should do?”

Take sparse notes

Don’t try to get it all. Record the locations of pauses and accidental clicks, and take down one quote from the user per task. At the end of each session, spend two minutes making notes of any missing observations. Patterns will become apparent with five users.

After correcting one thing, retest

Once there are five users, select the issue most likely to be serious for the user. Fix it. This repair may take a few minutes or hours.

Repeat with three new participants. Check that the fix was successful and didn’t cause problems with anything else. The “test-fix-retest” cycle drives usability work. A whole round may take place in a single day! Continue iterations until the critical workflows seem natural.

Use case: Jaguar Land Rover

Jaguar Land Rover (JLR) is a prominent automotive company. As part of digital transformation, it needed to modernize an outdated and slow manual testing approach in its complex SAP environment. They used the Tricentis platform for this automation.

Problem

JLR’s existing testing suite was not up to date with modern features, creating usability debt. One of the key challenges was manual regression testing. It was taking five to seven days to pass through a full cycle of testing. This method was slow and labor-intensive.

As a result, it affected project velocity, introducing risks to business-critical functions like finance, manufacturing, and after-market services.

Solution

In 2024, JLR decided to adopt three main Tricentis products: Tricentis Tosca to automate regression tests for core modules of SAP, NeoLoad to replace legacy LoadRunner, and Tricentis LiveCompare for change impact analysis, which includes SAP changes on business processes.

This gives stakeholders a usable dashboard, eliminating blind guesswork.

Outcome

The new platform provided substantial improvements, including:

• 80% accelerated project deployment. Regression testing was reduced from seven days to twelve hours.
• 40% of SAP application test automation coverage.
• 80% reduction in manual testing time.
• 15% more streamlined program delivery, plus shorter feedback cycles and increased release confidence for business units.

Positive feedback from various stakeholders shows that resolving the internal usability debt accelerated testing and, as a result, gave JLR the confidence to expand test automation to non-SAP applications.

You can read more about this case study here.

Agentic AI is not about replacing humans. We still need humans to interpret and plan strategically.

How does agentic AI enhance usability testing?

Agentic AI automates the entire usability research process, right from study design and participant recruitment to intelligent moderation and data synthesis. This improves usability testing.

The agentic approach leverages autonomous AI agents. Those agents can engage with hundreds of users simultaneously.

For example, it follows up with adaptive questions based on the participants’ responses, and it even runs a variety of user personas during the early testing phase without the need to recruit humans.

These agents can interact with biometric information, such as eye tracking. And they can automatically generate structured usability reports and provide proactive insight into interfaces to identify problems before formal testing even starts.

Agentic AI is not about replacing humans. We still need humans to interpret and plan strategically. Rather, it is about scaling research efforts, reducing analysis time from weeks to hours, and enabling ongoing, low-cost usability testing during development.

Have a look at how Tricentis helps teams validate user experience and software quality through AI-driven, end-to-end testing solutions.

Wrapping up

Usability testing isn’t just about finding out how a user interacts with a product. It’s the bridge that connects engineering logic to human intuition.

Observing real users as they use a system allows you to discover usability problems, confirm design decisions, and provide useful insight into user behaviour. That way, you’re able to create user-centred solutions.

Tricentis helps you automate and scale usability testing across web, mobile, and enterprise applications with tools like Tosca, Testim, and NeoLoad. Visit the Tricentis website to see more tools you can use to complement usability testing.

This post was written by Mercy Kibet. Mercy is a full-stack developer with a knack for learning and writing about new and intriguing tech stacks.