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Writer's pictureJakob Nielsen

What Is UX? (Part 1 of 2 of Jakob Nielsen’s UX Basics Article)

Summary: The information everybody should know about user experience, defining and explaining the terminology. It’s the definitive guide to show your boss or colleague who needs to understand UX. And it’s for aspiring professionals who seek to comprehend the essence of UX.

In the beginning, computers were the domains of engineers, crafted by techies for techies. User experience was not a whisper in the wind. That all changed when a handful of visionaries at Bell Labs dared to ask: what if we designed technology for humans instead of machines?

What is UX? Read on to learn. (Ideogram)


User Experience, known succinctly as UX, originated with the design of the touchtone telephone keypad at Bell Labs in the 1950s. There are now about 3 million UX professionals in the world, and the field is getting three times bigger each decade, a consistent growth trajectory spanning seven decades since the inception of UX.


What is UX? Why is it proliferating at such an exponential rate? What must you do if you wish to integrate UX within your organization? The simplest definition of UX is “we make computers easy to use,” but this statement barely scratches the surface. Continue reading for a comprehensive understanding.


(The concluding part of this UX introduction covers why and how to do UX.)


Our user: What is she doing, what is she thinking, what does she want and need? What is her experience with our product? UX provides the answers, allowing you to paint a vivid and profitable portrait of your customers in full color. (“Computer user” by Midjourney.)


The Genesis of UX

The term “user experience” was coined by Don Norman in 1993, but the discipline's roots trace back to Bell Labs’ hiring of John E. Karlin in 1945. (Other names, such as human factors engineering, were used earlier.) A few years after Karlin joined Bell Labs, that first hire had become a small team that worked on designing various telephony user interfaces from a human perspective rather than the purely engineering-driven projects of the past.

That’s UX: user-centered design that bases product definition and design on knowledge of human characteristics and user behaviors.


The design of the touchtone telephone keypad in the 1950s epitomizes UX. The Bell Labs human factors team designed many alternative keypad layouts in what we today would call the “diverge” design stage. They then proceeded to observe a large number of test users as they entered phone numbers with each of the design options. Test participants were timed, erroneously-entered phone numbers were recorded, and the users were asked about their subjective preferences.


Based on this research, the U.S. telephone company introduced new telephones with the keypad layout that performed best in user testing. Other countries copied this design, and it’s the one we still use today, even on mobile phones in the form of small flat-screen computers with no physical buttons to push. I estimate that this user interface has been used approximately 40 trillion times since it was designed. By picking the design that performed the best in empirical studies, the world has saved a collective one million person-years of time that would otherwise have been lost to quite reasonable designs that would have been slower for entering each of these 40 trillion phone numbers.


From the telephone company’s perspective, even more important than helping the world population by freeing up a million person-years for more happy activities, the company itself saved many millions of dollars during the first years after launching the new telephone design: when users can enter phone numbers faster, they block the central office switching equipment for less time, and those big telephony switches were super expensive back in the day.


At its core, UX applies the scientific method to the art of design, illuminating the paths people actually walk instead of assuming what they “must” want. Like an anthropologist, the UX researcher observes real humans in their native habitats. Only through this empathy can we design technology that feels like home.


The Duality of UX: Process and Result

UX has two sides: the process and the result. The latter is easy: UX simplifies technology. (The process is discussed in part 2 of this article series.) Some examples where UX can help:

  • Making it easier for patients and visitors to navigate a big hospital.

  • Making it easier for patients to understand the information about a new drug they were prescribed.

  • Making it easier for taxpayers to complete their tax returns. (Sometimes, I think the tax preparers’ association has bribed politicians to make the tax rules as complicated as possible. Still, if they bothered making this a priority, politicians could make the tax system easier for citizens by employing UX specialists in their rule-making process. And regardless of how crazy the rules may be, the tax authorities certainly can explain them better and make the forms easier through UX principles.)

  • Improving the check-in experience when arriving at a hotel.

  • Improving everything about a train journey, from finding out which trains run when, buying the ticket, navigating the train station, and understanding and using associated services like baggage shipping.

  • Making your electrical toothbrush easier to use.

  • Making an old-school manual toothbrush easier to use.

This last bullet (improving the design of a manual toothbrush) is usually considered industrial design — maybe with a dash of old-school human factors — and not a core example of user experience design. A traditional toothbrush has no user interface beyond simply grabbing and shoving it into your mouth. There’s not much so tricky that an average person might have trouble understanding it. Of course, a toothbrush still has a user experience, and behavioral studies can undoubtedly lead to better toothbrushing with a better-designed brush.


Even so, the usability problems compound with the fancy electric toothbrushes with multiple speeds and Bluetooth connectivity. Making those monstrosities easy to use is a true UX design problem requiring substantial user testing.


We usually identify UX with the design of digital products and services, especially with websites and mobile apps, because these designs have hugely more potential for complexity than almost any non-computer product. The more complexity and features, the more difficult the user interface is to learn and use. And the more we need to employ UX knowledge and methods to make it easier.


But in principle, anything people use creates an experience that can be better or worse, making it a valid target for UX work.


Defining UX vs. UI

The precise distinction between “user experience,” “user interface,” and “usability” is much debated on social media but doesn’t matter much. The real issue is the difference between user-centered design (as represented by all these terms) and engineering-centered or internally-focused design.


The core ideology of UX is that we take a user-centered approach to design, creating user interfaces for the way humans actually behave, as discovered through empirical research. We know how people behave because we study them, conducting observational research on representative customers performing representative tasks. If you design for “how people surely are” or “what I like myself,” you’re not doing UX design, and your product has a significant risk of failing in the market because it will likely be a mismatch for the actual customers.


User Experience” is a customer’s total experience when interacting with all a company’s touchpoints. This experience lives in each human, and different people may have different experiences using the same design. Thus, we can’t actually design the user experience, much as many people have the job title of “UX designer.”


Instead, we’re designing the various components that create the user experience, the most important of which is the user interface. The UI is simply what’s on the screen: buttons, labels, commands, menus, icons, and many more design elements, as well as the layout. The UI also includes the interaction design and workflow as users progress through multiple screens, the information architecture (IA) that determines how everything is structured, and the content design and visual design employed to present everything to the user. (In an auditory user interface, you replace “visual design” with “sound design,” and some of the other terms I mentioned may also differ when designing for other senses than the visual design that dominates most UI design.)


To appreciate the difference between UX and UI, consider a streaming audio service for playing classical music, such as Mozart’s symphonies. The UI is everything you see on the screen as you open the app: how do you navigate between Mozart and Beethoven? Do we use a word like “symphonies,” or do we call them “long-form music” to appeal to a broader audience? For that matter, is the primary IA by composer, performer, timeline (17th Century vs. 19th Century music), mood, form of music (opera, chamber pieces, etc.), or something else? Most likely, our user research with classical music fans will have revealed that we need all of the above, but how do we structure these options without being confusing? The same piece of music, say Beethoven’s 5th Symphony, may exist in thousands of recordings, so how do we handle this extra complication? Some users want to compare recordings; others just want the best one for various interpretations of “best.”


This is not an easy design problem, and we know that most current classical music services have been the target of severe criticism from fans due to inadequate design.


All the questions I mentioned above are UI design issues. But the UX has more to it. First, how well the service is populated with recordings and whether all the metadata is correct. Too few recordings and the experience is impoverished. Metadata bugs, and you can’t find what you want (creating a bad experience), even with a perfect UI that would work well with good data. The business model also matters: all-you-can-eat supports certain listening behaviors, whereas pay-per-play creates a different experience. And, of course, the sound quality of the audio files is paramount, especially for the audiophiles in the customer base.


Usability: UX’s Quality Compass

Usability is a quality attribute of the user experience. It has 5 components:

  • Learnability: The speed at which a new user can utilize the design, starting from zero knowledge.

  • Efficiency: The productivity level once the design is learned.

  • Memorability: The ability to return to the design after a hiatus.

  • Errors: The frequency, severity, and recoverability of mistakes.

  • Satisfaction: The pleasure derived from using the design.

All 5 are clearly things we want to maximize (we want to minimize the error rate). But depending on what we’re designing, the relative importance of the components will differ.


For example, a system that will only be used once must have extremely good learnability, whereas efficiency doesn’t matter much. On the other hand, an enterprise system that workers use all day, every day, should score high on efficiency, which will save you millions. It may matter less whether learnability is so low that the first day of use is for nothing since you have those workers on staff and can make them go through that first day with the promise of better things to come. (Don’t try that on web users: if they can’t use your website within the first few seconds of arriving at your homepage, they’ll leave the site and go to the next option listed on the search engine results page.)


Usability isn’t the only quality of a UX, but it’s essential. If people can’t figure out how to use your design, it may as well not exist.


At the same time, even if the design is easy to use, it’s also for nothing unless it has high utility, which is the measure of whether it accomplishes something that people want. Thus, usability and utility are both aspects of user experience, and neither alone will suffice.


UX Makes Life Better

UX blends science and empathy into a potent elixir, enhancing technology from a curse into a cure. It carves through engineering dogma to the human truths beneath. Is it the most important thing in the world to make technology easy to use? Maybe not, but it’s what we do. And in creating products built for real people, UX breathes purpose and pleasure back into digital life. By doing so, UX will also nicely increase your company’s profits.


Your Chief Financial Officer will enjoy what embracing user experience will do to the company bank account. (“Happy CFO with money” generated by Leonardo.AI.)


A Poem to Summarize Part 1

Two sides hath UX, both process and result, A simplifying art, a guiding hand, In hospitals, in trains, without insult It leads us through complexities unplanned. From toothbrushes to taxes, apps to trains, Its touch is felt in every walk of life, A gentle hand that soothes, relieves our pains, A calming voice midst digitalized strife. Yet not just digital, its reach extends, To objects, places, services we use, A universal friend that comprehends, The human heart, and never does abuse. In UX we find a thoughtful guide, A friend in whom we can confide.


UX, a blend of science, art, and heart, A cure for tech's cold, unfeeling embrace, A human touch, a start, a work of art, A path that leads to a more joyful place. It breathes new life into our digital sphere, It gives us purpose, pleasure, and delight, It whispers in our ear, "I'm here, I'm near," It turns our darkest digital night bright. And profits too, it brings, a happy gain, A CFO's delight, a wise investment, A path to growth, success, a golden vein, A future bright with promise and advancement. So let us raise a toast to UX, our friend, A journey's start, a means, a joyful end.


Part 2


Infographic to Summarize This Article

Feel free to copy or reuse this infographic, provided you give this URL as the source.


About the Author

Jakob Nielsen, Ph.D., is a usability pioneer with 40 years experience in UX. He founded the discount usability movement for fast and cheap iterative design, including heuristic evaluation and the 10 usability heuristics. He formulated the eponymous Jakob’s Law of the Internet User Experience. Named “the king of usability” by Internet Magazine, “the guru of Web page usability" by The New York Times, and “the next best thing to a true time machine” by USA Today. Before starting NN/g, Dr. Nielsen was a Sun Microsystems Distinguished Engineer and a Member of Research Staff at Bell Communications Research, the branch of Bell Labs owned by the Regional Bell Operating Companies. He is the author of 8 books, including Designing Web Usability: The Practice of Simplicity, Usability Engineering, and Multimedia and Hypertext: The Internet and Beyond. Dr. Nielsen holds 79 United States patents, mainly on making the Internet easier to use. He received the Lifetime Achievement Award for Human–Computer Interaction Practice from ACM SIGCHI.



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