There are many definitions of user experience, some broad, some narrow, none of them UI. Here are the ones that matter, plus a simpler one of our own.
User experience is a person’s perceptions and responses that result from using, or anticipating using, a product, system or service (ISO 9241-210). Norman and Nielsen define it as all aspects of the end-user’s interaction with a company, its services and its products. UX is not user interface and not usability; those are small parts of it.
Key takeaways
- There is no single definition of UX; ISO, Norman/Nielsen and Wikipedia each frame it differently.
- The common thread: UX is about a person's perceptions and responses, before, during and after use.
- UX is not UI and not usability. Both are small components of UX.
- A useful definition centers psychology and the idea of a need being created or satisfied.
- UX happens on the user's side; designers design experiences and then measure them (that is UXD).
The Norman and Nielsen definition
User experience encompasses all aspects of the end-user’s interaction with the company, its services, and its products.
Don Norman and Jakob Nielsen, Nielsen Norman Group
The Nielsen Norman Group makes an important clarification alongside this definition: user experience is not user interface, and it is not usability either. In other words, UX is not UI. Both usability and interface design are small parts of UX as a whole.
ISO standards in user experience
ISO 9241-210:2010 defines UX as a “person’s perceptions and responses resulting from the use and/or anticipated use of a product, system or service.” It adds three notes: UX includes all the user’s emotions, beliefs, preferences, perceptions and responses before, during and after use; it is a consequence of brand image, presentation, functionality, performance and the user’s prior state; and usability, seen from the user’s personal goals, can include the emotional aspects associated with UX.
A common (Wikipedia) definition
Wikipedia frames UX as a person’s emotions and attitudes about using a product, system or service, including practical, experiential, affective and valuable aspects of human-computer interaction. It notes that UX is subjective and changes over time as usage and context change. It is correct but somewhat dated, and common in computer-science contexts.
Our definition
User experience is the sum of subjective perceptions that a person has about a product, service or system designed to create or satisfy a need.
Fabio Devin, Dorve
This definition is grounded in psychological and economic theory. Any UX definition that does not treat psychology as central is likely incomplete, because UX is fundamentally about measuring users’ subjective perceptions and emotions. Economic theory adds the value users place on experiences. And the idea of a need matters: the experience must have intentionality and purpose. Without intention, you can still measure a system, but you are not designing a meaningful experience.
Is UXD the same as UX?
No. Saying “I work on UX” or “I will create the UX” is technically wrong, because UX happens on the user’s side; you cannot directly create it. You design an experience and measure its effects, and that measurement is UX in practice. The precise roles are UXD (designer), UID (interface designer), UXR (researcher) and UXE (engineer). UXD is far more accurate and professional than “UI/UX” or “UX/UI”.
In summary: what makes something UX
- User: who the experience is directed at.
- Experiencer: who creates the experience.
- Intentionality: the reason the process is undertaken.
- Design: how the process is developed, including prior research and later measurement.
A person’s perceptions and responses resulting from the use or anticipated use of a product, system or service (ISO 9241-210). It spans emotions, context and time, not just the interface.
No. User interface design and usability are small components of UX. UX covers the whole relationship between a person and a product or service.
ISO 9241-210 defines UX as a person’s perceptions and responses resulting from the use or anticipated use of a product, system or service, including emotions before, during and after use.
UX happens on the user’s side and cannot be created directly. UXD (User Experience Design) is the professional practice of designing an experience and measuring its effects.
The term was popularized by Don Norman, and the Nielsen Norman Group offers a widely cited definition. ISO 9241-210 provides the formal standard.
Want UX grounded in psychology and data, not buzzwords? Talk to Dorve.
Start a project