What is UX?

TL;DR

UX (User eXperience) is a discipline that focuses on understanding users’ emotions, reasoning and behaviors, and then designing solutions that truly meet their needs.

Key takeaways:

• UX isn’t limited to screens: it covers every interaction between a human and a product, a service or an organization
• It rests on two complementary pillars: user research (understanding) and design (designing)
• Its goal is to make interfaces (physical or digital) useful, usable and satisfying in real use
• UX is a strategic investment: fixing a problem after launch can cost up to 100 times more than catching it upstream

What is UX? Definition and origins

Don Norman’s founding definition

“User experience” encompasses all aspects of the end-user’s interaction with the company, its services, and its products. — Don Norman, who coined the term User Experience (1995)

The word “user” is often associated with the use of software or an application. But as Don Norman points out, UX covers all the interactions between a company, its services and products and the end user. We are users when we ask a salesperson for advice, when we wait in line, or when we unbox a package.

The standards-based definition: ISO 9241-210

The ISO 9241-210 standard (2019) offers a more formal definition:

User experience refers to a person’s perceptions and responses resulting from the use and/or anticipated use of a product, system or service.

Two points that often get overlooked:

1. Anticipation matters. The experience starts before the user even touches the product. The ad they saw, a friend’s recommendation, the expectation they build up: all of that is part of UX.
2. Perceptions are subjective. Two users in front of the same product can have radically different experiences. That’s exactly why user research is essential: you can’t guess what people feel.

UX vs UI: an essential distinction

The confusion between UX and UI is probably the most common misunderstanding in our field.

UI (User Interface) refers to the visual interface the user interacts with: buttons, colors, typography, animations. It’s what you see and what you touch.

UX (User eXperience) covers the user’s entire journey and lived experience. UI is part of it, but it’s only one component among many.

Picture a restaurant. The UI is the plating, the dining room decor, the menu design. The UX is the full experience: how long you waited for a table, how you were welcomed, the quality of service, the taste of the food, the bill, and even the memory you keep of it three days later.

An interface can be visually stunning (great UI) and still be confusing to use (bad UX). Conversely, a sober, minimal interface can deliver a smooth and satisfying experience.

In my view, splitting UX and UI designer into two separate roles is pointless. I see this role as a whole. I prefer to talk about Product Designer, full-stack designer or simply designer. People who take on this role need to be able to do both research and design work. Specialization exists in larger organizations, but versatility is still the key to being effective.

The 2 pillars of UX: Research and Design

UX rests on two fundamental activities that feed into each other. Research produces knowledge: reports, syntheses, experience maps that help you understand the problem. Design produces solutions: interfaces, prototypes, interactions that respond to the identified problem.

One without the other doesn’t work. A designer who only designs without ever talking to users ends up designing for themselves. A researcher who never gets involved in design produces knowledge that stays in a drawer.

Research: producing knowledge

User research means going out into the field to understand users’ behaviors, motivations and frustrations. It produces knowledge deliverables: interview write-ups, experience maps, personas, analysis grids.

It draws on several skills:

• Empathy: understanding and sharing users’ emotions. It’s a mindset that you build, especially through active listening.
• Collection: structuring how you gather feedback, whether quantitative (analytics, surveys) or qualitative (exploratory interviews, field observation).
• Synthesis: turning hours of interviews into readable, shareable documents.
• Testing: observing how users interact with an interface without biasing them. User testing is an art in itself.

Without research, you’re designing blind. It’s like building a house without knowing the terrain or the future residents’ needs.

Design: producing solutions

Design covers all the activities that produce concrete answers to the identified problems. It produces solution deliverables: wireframes, mockups, prototypes, interaction specifications.

It draws on several skills:

• Information architecture: organizing content so it’s easy to find and understand (sitemaps, user flows, card sorting).
• Interface design: building screens that are useful, usable and consistent (wireframes, visual mockups).
• Prototyping: simulating how a system works in order to test it (prototypes on paper, in Figma, etc.).
• Interaction design: designing transitions, states (loading, error, success, empty) and the logic of the journeys.
• Visual design: shaping the interface through typography, color, icons, in a way that’s consistent with the brand.

The Research + Design cycle

These two pillars are cyclical. A designer doesn’t do “research first, then design”. They constantly alternate between the two:

1. Research: exploratory interviews to understand the field
2. Design: sketches, wireframes, prototype
3. Research: user testing on the prototype
4. Design: improvements based on the feedback
5. Research: usage metrics in production
6. Design: continuous improvements, and so on

This cycle sits at the heart of Design Thinking. Each iteration reduces uncertainty and brings the solution closer to the real need. The earlier you iterate (with quick, cheap prototypes), the lower your risk.

The amount of time spent on each pillar shifts depending on the project’s stage. Early on, you spend much more time on research than on design (typically 70/30). As the product matures, the ratio flips. But research never goes away.

UX in practice: good and bad examples

A bad journey: forced sign-up

You’re looking for a product on an e-commerce site. You find it, add it to your cart, and click “Check out”. And then you’re asked to create an account with a password, email confirmation, and 12 fields to fill in. You give up.

Jared Spool documented a famous case: an e-commerce site replaced the “Sign up” button with “Continue” and dropped the mandatory account creation. Result: +$300 million in revenue in the first year. The product didn’t change, the interface didn’t change. Only the journey was simplified.

A good journey: Duolingo’s onboarding

When you open the app, Duolingo doesn’t ask you to create an account. It asks you 3 questions (which language, what level, what goal), then drops you straight into a lesson. You only create your account after finishing your first session, when you’re already invested. Research has shown that the earlier a user invests in a product, the more likely they are to stick around.

A failed vs successful error message

Failed: “Error 422: Invalid field.” The user has no idea which field is the issue or what to do.

Successful: “We need your email address to continue.” The user immediately understands the problem and the solution.

Same information, radically different experience. The feedback an interface gives the user is one of the most underrated UX levers.

Accessibility: an essential part of UX

Digital accessibility is about making interfaces usable by everyone, including people with disabilities: visual, auditory, motor or cognitive. It’s not optional, and it’s not a “nice to have”. It’s both a legal obligation and a lever to improve the experience for all users.

Why every designer should care

• 15% of the world’s population lives with some form of disability (WHO). These aren’t edge cases.
• In Europe, the European Accessibility Act (Directive 2019/882) makes accessibility mandatory for digital products and services starting in June 2025. In France, the RGAA (Référentiel Général d’Amélioration de l’Accessibilité) is the reference framework.
• Accessibility best practices improve the experience for all users. Sufficient contrast also helps people checking their phone in bright sunlight. Plain text also helps non-native speakers. Keyboard navigation also helps power users.

The basics to know

• Contrast: a minimum ratio of 4.5:1 between text and its background (WCAG AA). Test your mockups with a tool like Stark or the Figma contrast checker.
• Alt text: every image should have an alt attribute describing its content for screen readers.
• Keyboard navigation: anything that’s clickable should be reachable from the keyboard (Tab, Enter, Esc). Test your interface without a mouse.
• Heading hierarchy: use h1, h2, h3 levels in order. Screen readers use them to navigate the page.
• Touch target size: at least 44x44 pixels on mobile (Apple and WCAG recommendation).

Accessibility isn’t an audit you run at the end. It’s a design habit you bake in from the start, the same way you check spelling as you write.

Why UX is a strategic investment

UX isn’t a luxury. It’s a measurable performance lever.

42% of startups fail because they don’t address a real market need (CB Insights, 2021). User research is precisely designed to avoid that trap.

Fixing a problem after launch can cost up to 100 times more than catching it during the design phase (IBM Systems Sciences Institute). An upstream user test would have flagged the issue in a few hours.

Every dollar invested in UX returns between 10 and 100 dollars (Forrester Research). That ROI comes from lower support costs, higher conversion rates and better retention.

These numbers give you concrete arguments when you need to convince a client or a manager to invest in a UX approach. To structure that argument, see the article on how to answer a client.

Common misconceptions about UX

”UX is making wireframes”

No. Wireframes are one tool among many. Doing UX is, first and foremost, understanding a problem before proposing a solution. Sometimes the most important deliverable isn’t a wireframe but an experience map or a list of strategic recommendations.

”UX is just common sense”

If it were just common sense, why are so many products frustrating to use? “Common sense” is shaped by our own experience. User research exists precisely to push past those biases.

”UX slows the project down”

It’s the opposite. A project without UX moves fast at the start, but builds up an experience debt that gets more and more expensive to fix. A project with UX invests time upfront to save a lot more downstream.

”We’ll do UX later”

UX isn’t a coat of paint you apply at the end. It’s an approach you carry from day one, when the structural decisions are still on the table.

The designer’s role on a team

The designer isn’t an executor who receives a brief and “makes the mockups”. Their role is far more strategic.

Upstream, they help frame the problem, identify the hypotheses to validate and plan the user research.

During design, they facilitate ideation workshops, produce wireframes and prototypes, and run user testing.

During development, they support the developers, clarify edge cases, and make sure the design intent is preserved.

After launch, they analyze usage metrics and identify the next improvements.

In short, the designer is a translator: they translate user needs into concrete solutions, and they translate technical constraints into design decisions everyone can understand.

Going further

• Design Thinking: the framework that structures the UX approach
• Active listening: a fundamental technique to understand users
• Exploratory interviews: the first concrete user research tool
• User testing: to validate your design hypotheses
• The experience map: to synthesize what you’ve learned from research
• Personas: to put a face on your target users

Sources

• The Definition of User Experience (UX): NNGroup
• ISO 9241-210:2019: Ergonomics of human-system interaction
• CB Insights (2021): Top Reasons Startups Fail
• IBM Systems Sciences Institute: Relative Cost to Fix Defects
• Forrester Research: The ROI of UX
• Spool, J. (2009): The $300 Million Button
• WHO: World Report on Disability
• EU Directive 2019/882: European Accessibility Act
• WCAG 2.2: Web Content Accessibility Guidelines