Benefits, mistakes to avoid, and examples. And this article will provide you with statistics in addition to concrete cases and metaphors to prove it to you.
A bonus ? A client will be joining our User Testing webinar on March 12, 2026, to discuss their journey in implementing user testing. They will explain how the process began, the obstacles they encountered, and most importantly, the benefits they gained.
Here's the link if you're interested in hearing about a field experience: This is where you can register!
Getting back to this article, I'd like to start with a question for you…
Designing without user testing: a leap into the void
Imagine you're on a plane, I give you a parachute, and you're going to jump in the next two minutes. A little stressed, I have to say. And then I tell you that nobody has ever tested the parachute you're about to jump on. utiliserBut I assure you it was designed by the best engineers. Solid materials. Precise calculations. Industry best practices.
I really promise you: everything will be fine.
Are you jumping?
Yet, this is precisely the risk that many companies still take in the digital realm. They dedicate months, thousands of euros, a lot of energy, investment… and ultimately launch solutions validated by theory, but which have never encountered the reality of a 4,000-meter fall.
Expertise has its limits: why users remain indispensable
Why aren't UX experts enough?
You might say, “But we pay UX experts to design these interfaces; it’s their job.” That’s true. But there’s a fundamental difference between expert design and actual usage. Even with the best UX designer in the world and all their knowledge of cognitive psychology, it’s impossible to predict every human behavior. However competent they may be, relying solely on their expertise is a risk. Why? Because the quality of the analysis depends directly on their experience, their references… and their own biases.
The expert relies on heuristics and standards. The user, however, arrives with their own mental models., its stressful context, its interruptions and its illogical habits.
The expert will try to anticipate the user's needs and reactions as much as possible, but they are not the user. Nor are they all users.
It's a prediction, but it needs to be validated with real people who will be using your product or service tomorrow to ensure it's accurate. If you don't meet with them for validation, you're launching blindly. That's risky. Very risky.
User tests vs. expert reviews: different results
A survey shows that user tests detect 70% of major problems, against only 12% for expert journalsThere is some overlap between the problems identified during expert analyses and those identified during usability testing, but this is estimated at only 41%In other words, user testing does not replace UX expertise, it complements it.
Decide based on the facts
Beyond error detection, User testing is a powerful internal toolYou may have already experienced these situations: hesitating for hours between two options, endless meetings, and debates about the best solution… User testing settles the debate. Conducted rigorously, with multiple participants and a comprehensive analysis, it provides a factual, observable, and difficult-to-refute answer. This saves you time.
In the scientific world, this would seem unthinkable. No drug, no medical device, no serious industrial product is ever marketed without testing. In digital design, the principle is the same. Test early, test often, and let real-world experience guide your strategic choices rather than assumptions made in the boardroom.
The limits of expertise in professional contexts
In the context of business software, this gap is even more difficult to bridge.
A UX expert has often never been:
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field operator
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support agent under pressure
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accounting during closing period
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logistics expert facing an emergency
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or user of a business tool for 8 hours a day
He doesn't know the makeshift shortcuts, the habits, the terms adopted by the employees… If we really want to meet the needs of users, the simplest thing is still to go and see them and listen to them.
What are the concrete benefits of user research?
A profitable investment
You might be wondering if all this is really worth the investment, and rightly so. Is it an unnecessary expense to make things look shiny? Or is it just a hunch?
Even though user search is not easy to quantify, it is widely documented. For example, a survey shows that companies that integrate it are 20% more likely to increase their revenue compared to those that do not. other study claims that a site integrating UX and its users can increase its conversions by up to 400%.
You will also find here a comprehensive article detailing the ROI.
The critical importance of business software
As you've probably gathered, UX research saves time, improves revenue, and increases satisfaction. But you likely already know that. What's less often considered, however, is that these effects are significantly amplified in business applications. Why? Because these business applications are used:
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daily, sometimes 40 hours per week
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by users under pressure, in real-world operational contexts
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for very specific uses, often far removed from web standards
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and with direct consequences in case of error (lost time, operational errors, stress)
In this context, a few seconds wasted on an action repeated hundreds of times a day quickly translate into hours of lost productivity each week. But it's not just users who waste time. On average, 80% Many features of SaaS software are rarely or never used. In other words, a huge portion of the development effort produces a marginal or zero return in terms of user engagement.
This Article This fascinating example shows how relevant UX/UI improves both business performance and the daily lives of employees.
The “Delivery Gap”: when the company turns a blind eye
The problem isn't just technical or ergonomic. It often stems from a profound gap between internal perception and the reality experienced by users. This is what's called the Delivery Gap.
A study A study conducted by Bain & Company clearly illustrates this phenomenon: 80% of companies believe they offer a “superior experience,” while only 8% of users share this feeling. In other words, many organizations make decisions based on internal beliefs, without any real-world experience. User research allows us to bridge this gap by replacing assumptions with observable facts.
Concrete examples: when reality contradicts the design
A natural phenomenon of user observation
You've probably already seen this kind of thing in a park or on a street corner.
Paths carved into the grass reveal a layout not entirely suited to the actual uses of the space. A disconnect between the initial intention… and the reality on the ground. This is what we call… desire lines.
They appear when architects design beautiful, straight, paved walkways, and pedestrians cut across the grass to save a few seconds. How could this have been predicted? By observing actual usage. By testing. At Ohio State University, the architects initially planned geometrically laid walkways that intersected in an X shape. But due to budget constraints, no paths were laid out. For a season, the students simply walked on the grass. Gradually, paths emerged, reflecting their actual usage, which was very different from what had been planned. A full-scale user test. They then simply paved where the grass had disappeared.
What's the point of paving beautiful, straight walkways if users walk right past them?
Case studies: 3 proofs by example
In the digital world, these paths often take much more subtle forms. Here are three cases where user testing proved beneficial. (For an even more concrete example, told by a client himself, the link to our webinar is just below 😉)
Website for young parents
On a website for young parentsThe UX experts had approved the user journey. Smooth navigation, accessible buttons—everything seemed logical according to web standards. Then, real users tested the site. The result? “It’s so insensitive!” “I’ll never use this site again.” Why? An advertising banner for a local gym right next to an article about breastfeeding. For an exhausted new mother, sleeping only two hours a night and trying to breastfeed, it felt like a guilt-inducing pressure to lose weight immediately when she barely had time to shower. The expert sees an advertising space. The user has an emotional experience. Without testing, you risk insulting your customers without even realizing it.
E-commerce
It probably is the anecdote The most famous UX story, as told by Jared Spool. A major e-commerce site was losing customers in droves at checkout. They simply assumed users were changing their minds. User testing revealed the cause: the mandatory login form before purchase. The team thought they were doing the right thing: “This makes it easier for customers to return.” But in reality:
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New users saw this as a major constraint, “I’m not here for a relationship”.
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Existing customers no longer remembered their passwords and were giving up out of frustration.
By replacing the “sign up” button with “continue as guest,” the number of purchases increased by 45%, generating $300 million in additional revenue in the first year. Sometimes, changing a word is all it takes to change a business.
Mozilla Support Service
On the Mozilla support siteThe support service was overwhelmed with repetitive requests. Through iterative usability testing, the teams completely redesigned the information architecture of the help site. As a result, the volume of support requests dropped by 70%.
Conclusion: Include users in your thinking
All solutions designed for humans (digital or otherwise, websites, mobile applications, business software, etc.) deserve to be designed with them in mind. Observing end users in real-world situations is the best way to avoid errors, minimize bias, and optimize investments. You save time, money… and the trust of your employees.
What's next?
If you are convinced of the value of user testing, it is time to address the subject in an operational manner.
In our next webinar, we will demonstrate how to integrate user testing into a project, with customer feedback to illustrate the approach.
Julie Petetin, UX/UI consultant at UX-Republic
