The question is coming up a lot recently “what is user experience?” And in the same breath—promoted by the alliterative experience of saying “UXUI”—”what is the difference between UX and UI?”
I’d like to try to answer this with an analogy to the act of building a house.
To build a house right, you need to know what your house is going to be used for. The house also needs to be strong and sturdy, and—to be enjoyed to the fullest—it needs to be pleasantly decorated and furnished. In my analogy, that comes down to three roles:
- You hire an architect to plan the house.
- You have a structural engineer to make sure all the supports are in the right place.
- You hire an interior decorator to specify colors and finishes and fixtures.
In my analogy, the interior decorator is the user interface designer (UI). The structural engineer is a lead developer. And the architect is a user experience (UX) practitioner.
An architect will ask you questions about the requirements and conditions for your house:
- How many people will be living here?
- What are these people like: young, old, tall, short, given to entertaining or quiet and reclusive?
- How will the occupants use the house?
- What is the climate like where the house is to be built?
- What is the site like: is it hilly or flat? Wooded or wide-open? What direction does it face?
Based on the answers to these and other questions, an architect will design a home for you with a set number of bedrooms and bathrooms, kitchens and office spaces and playrooms as needed, and windows as desired to take advantage of the site. There will be indications about the location of doors and the sides on which they are to be hinged. Needs for power outlets and the suggested placement of plumbing fixtures will be described. These are user experience elements: they define how spaces will be used in a way that is about function or interaction. And although they can be changed they are mostly fixed.
The engineer would make sure that the planned spaces could be built and wouldn’t collapse. Mostly these elements are unseen by the user/resident. Some decisions about the experience will force structural requirements. Sometimes limitations of the structure will require rethinking of the exact details of the experience. (And sometimes capabilities of the structure will offer up new ideas for the function.)
The decorator would plan textures and colors for walls and furnishings. This is the user interface (UI). The user interface is touched and observed by the user. It can be changed superficially without impacting function or interaction. Sometimes it can change the interaction in modest ways. It is a major component in how the user/resident feels about the space.
(Note that there can be overlap across the three areas: Ideas about the colors of a wall might suggest a decision about the placement of a window which could set up certain structural requirements. Furnishings (UI?)—couch versus bed—certainly imply the function (UX) of a room, even in opposition to its location (UX?)—near the front door or upstairs in the back! And sometimes an architect (UX) designs special furniture (UI) for their creations. This overlap is one of the benefits of a small team working closely together, feeding each other ideas and not locking one element entirely before getting input from the others.)
But if your architect (UX) forgot to include a bathroom, no amount of work by the decorator (UI) could make living in that bathroom-less home a better experience. Or if the engineer noticed that the plans didn’t include a kitchen, she might find a place to fit one in, maybe in a place that was structurally simple but not ideal for use by the occupants. No amount of user interface can improve the experience of a home without a bathroom.
So user experience is different from the user interface. The two go hand-in-hand, since the user’s experience of a home will be affected by both the utility (dare I say “usability?”) of that home and the aesthetic aspects of design.
And user experience and development need to work together. While any good architect will have an understanding of physics and gravity and such, it’s not their specialty. And while no good engineer will let a house be built without a bathroom, there are finer points about homes—such as the direction doors should swing—that are irrelevant to the structural component of building.
In summary, User Experience takes a broad set of requirements, adds detail through research, and generates a plan for a piece of software—the house’s rooms, hallways, doors—which meets the needs of the user. We are aided by User Interface design, but UX and UI are not the same: a good user experience is not created by good visual design alone. And a good experience for the user is vitally supported by good development, but even brilliantly-coded software does not guarantee that the user can reach their goals. By understanding in some detail their goals and tasks, we deliver a plan for software which satisfies the explicit and implicit needs of the user.
