I’ve been working on website and app design since 2012, and I’m still surprised by the confusion between User Interface (UI) and User Experience (UX). Occasionally you’ll find pithy diagrams like the two Heinz ketchup bottles or the pleasure path photo that muddle the basic definitions of UI and UX. Strange questions sometimes pop up, like “Can you design a terrible UI and a great UX?” or “How can you design an experience?” Quora.com and Medium.com have many posts about this conundrum, including this great rant. Many of the explanations come down to roles and responsibilities of UX and UI designers, but many designers don’t fit neatly into any role, nor do they want to.
Let’s start with definitions
In a typical day you could use any of these interfaces: a faucet handle, a zipper, shoelaces, a door knob, a lock, a steering wheel, a pedal, a power button, an app icon, a keyboard, a mouse, a trackpad, a power plug, a credit card swiper, a thermostat button, a TV remote, and a light switch.
In that same day you could have these experiences: Turning off an alarm clock, having a hot shower, dressing for work, leaving a house, driving to work, turning on your machine, using a credit card, adjusting the thermostat, browsing a video app, and reading a book.
From these examples we can see that UIs are tangible nouns; they are the basic things we touch to get little jobs done. UXs are the temporal verbs; they are events that happen with UIs. Every time you touch a small UI you’re also having a small UX. We’re surrounded by dozens of small UIs and UXs, and most of them are good at doing their little jobs.
UIs are tangible things we act on.
UXs are actions we sense over time.
With these definitions in mind, let’s take a look at three case studies that show the relationship between interfaces and experiences within different forms.
Case Study 1: Door Knobs
With this basic definition of UI and UX, let’s take a closer look at an old example, the door knob. The form is a hinged door within a frame. The essential UI is a latch that fixes a door closed. This UI could be as simple as a nail with a string, but we expect better. A good door knob requires several small UIs working quickly in concert: a graspable handle, precise rotation, fast unlatching, a sprung reset of the latch, durability, unobtrusive gripping, and contextual aesthetics. Screw any of those up and you’ll likely affect the simple UX we’re so used to.
You can see from the photographs that the UIs of the door knobs have changed significantly over time. Towards the end of the sequence the latch hardware disappears altogether inside the door, and all you to do is twist the round knob. It’s an example of a fairly complex UI that is simple and easy to operate. Good UIs lead to good UXs, and the best UIs just disappear. For a diversion on that topic, check out the book Don’t Make Me Think.
Case Study 2: Opening a phone
Consider a parallel example of opening your phone. It’s an action we do dozens of time a day, so a good UI is a matter of saving time. Take a look at the difference between an iPhone 6 and a classic flip phone. Many people remember the great ease of just flipping the phone open to receive a phone call.
This is an apples-to-bananas comparison; the two phones have different forms and methods of operation. But the difference between the two phones shows how form factor can influence which UIs and UXs are available. The iPhone 6 cannot use the faster and easier flip operation because it would become thicker and unwieldy.
For a diversion on form-making decisions, check out the book Notes on the Synthesis of Form or this medium article about that book.
Case Study 3: Designing a vehicle
For the final case study, let’s imagine that you’re designing a vehicle to move a person quickly around a city. Ignoring the engineering aspects for a moment, you would need to answer some big questions around the interfaces. Will the person sit, stand, or recline? How is the vehicle powered? How does the person pilot the vehicle? There are numerous possible vehicles that will accomplish the design objective, and each will come with unique UIs and UXs. As you answer these questions, the form will start to take shape.
Somewhere in the form making process, the designer will wonder about the experience. Is this thing fun or boring, fast or slow, breezy or claustrophobic, heavy or light? You can try to assign these experiences beforehand, but they are meaningless until tangible parts and formal decisions are involved. In this case study, trying to put the cart before the horse will get you nowhere.
Can UI and UX design unite under one name?
I’m not sure when the distinction between UI and UX occurred but it’s a fancy mirage that confuses everyone. I hope for a simplified title such as “software designer” that increases responsibility and throughput. The closer designers become to the bits and pieces of software the better we can compose them into great experiences.
