A few weeks ago Microsoft released a video showcasing their idea of what the future of technology might look like. Some weeks later, Bret Victor wrote a rant about how unimaginative Microsoft’s vision is. The thrust of his argument is that the ubiquitous touchscreens depicted in the video are uninventive because it disregards the most fundamental and powerful tool known to man: our hands. He explains that the physical interfaces of today don’t take advantage of our hands’ ability to both feel and manipulate things.

All this talk about hands and feeling and manipulation got me thinking. Given the current state and inertia of technology, it should be our foremost goal to make our interfaces feel good.

Feeling is often the indescribable property that separates a good interface from a great one. It’s the gap between the pixels and your finger (or mouse, by extension). You hear people mention this all the time when talking about software; “I don’t know, it just feels good”. Of course they’re not actually talking about how it feels, they’re talking about how their brain perceives it would feel if it were a physical interface. They’re talking about how well it responds to their input.

Without tactile feedback, as is the case when using a touchscreen or navigating a mouse cursor around a screen, our brain can’t depend on our hands and instead relies on our eyes to proxy visual feedback. We use this information on a subconsious level to confirm our last action and plan our next one. How an interface feels is the fidelity of the visual feedback to how our brain predicts it should feel.

It’s easy to see how important visual feedback becomes to the user experience in the absense of tactile feedback. It explains why skeuomorphism has prevailed as a common user interface design approach: it’s comforting to us as users when what we see and feel in the virtual world matches our perception of the physical world. This is why buttons often look like buttons and calendars often looks like calendars.

But how an interface feels goes deeper than the pixels on the screen; it’s all about trust. As an interface designer, you enter a contract with your users. Your design implicitly guarantees the user: “When you click X, the software will do Y”. It’s the job of your interface to back this guarantee by providing the feedback necessary for the user to feel assured you kept your end of the bargain. The gap between what your UI promised and what was delivered is received by the user as negative feeling. We’ve all experienced it, that brief moment of cognitive dissonance when you beckon the software to do one thing and it appears to do something different, or worse, nothing. That’s broken trust.

I have long preached that every clickable element (links, buttons, etc) deserves at least three states: idle, hover and click. I also encourage additional states for active-hover and active-click, but they are less necessary. Even novice designers know to make the idle state of their links obvious, but it’s surprising how many neglect to provide the user proper hover and click states. The hover state signifies that the element is clickable at this moment and the click state confirms that the element was clicked, both of which are crucial to keeping up your end of the UI contract.

The very best user interfaces are those that have a two-way conversation with the user, with equal transmission amplitude from both parties. When the visual feedback provided by your interface falls short of what the user expected, you’ve subconsciously broken their trust and left them with an indescribable feeling of doubt.