Software is often (though not always) designed using some sort of metaphor to give users some context, something familiar to recognize early on. The idea is that a more familiar interface will lead users to a quicker understanding of the software and what it’s about. The metaphor may also give users the sense of comfort that familiarity is supposed to breed (it is comfort, right?). Examples include the Windows desktop, which is supposed to look and act like a desktop; Excel, which looks like a ledger, or maybe just a pad of graph paper; and the contacts app on my iPhone that looks like an address book (or at least it used to).
The choice a designer makes about how to represent context in software makes a significant difference in usability. A well represented metaphor can give a user a reference point, something to help make software more accessible. Early understanding will come easier. Users see an interface and quickly think “Oh, OK. I get it.”
But as soon as that metaphor breaks down, and the connection to the real world is lost, the user becomes disoriented, and gets lost in the software. Sometimes that happens immediately: the Windows desktop doesn’t look like a desktop, it doesn’t work like a desktop, and the metaphor doesn’t hold. The same can be said for the Mac desktop. Neither is anything like an actual desktop. The metaphor has very little value, and the functionality of these “desktops” is easiest to understand if you just ignore the metaphor altogether.
There are other options. One is to forget about metaphors altogether, and let the software explain itself in other ways. Just make things easy to use, without focusing on holding a possibly tenuous connection to the real world.
This is the approach that Jonathan Ive prefers at Apple, and apparently there was some disagreement between Ive and Steve Jobs about skeumorphism: designing apps to look just like their real-world counterparts. The iPhone contacts app looked like an address book, the notes app looked like lined paper, and the calendar app looked like an expensive, leather-bound, paper calendar. They used to be skeumorphic, but Jobs is gone, and Ive has made some changes.
Eschewing metaphor works well, especially for simple apps on a smartphone. The metaphor can be distracting, or act only as window dressing, without improving usability at all. App designers have no trouble keeping app interfaces simple and easy to understand, without need for a visual link to the outside world.
But honestly, where’s the fun in that? If software takes a more literal approach, and provides a visual representation of the real world, the reference point can be established more deeply. If the connection to the real world can be held, the understanding will hold, too. As long as visual context is consistently represented, software remains accessible, understandable, and ultimately more usable.
Video games balance this equation a bit differently than most enterprise software and productivity apps. Games are often fully representational: they put you in a world that looks and behaves just like the real world. It’s extreme skeumorphism. Actually, it’s just realism. In 3D games you’re fully immersed (or at least somewhat immersed, depending on the quality of the game) in an environment. You interact with representations of things that are designed to look just like those things do in the real (or imaginary or fantasy) world. The more those things look and act like their real or imagined counterparts, the better the experience.
But all the while, video games present players with an added layer of interface, using heads-up displays (HUDs) and menus and mouse, keyboard, and touch interactions. None of those need to be exact representations of the real world. In fact, because the illusion of immersion works better with fewer distractions, HUDs and menus and any other UI elements are often minimal, hidden, or even semi-transparent. They cloud the action, so we keep them out of the way. You see only what you need to see at any given moment.
In video game UI, metaphor doesn’t help. A good HUD is easy to understand, but it does not necessarily correspond to something you might see in the real world. Even the most exceptional HUD proves the rule: in some first-person shooters there is a HUD that looks just like the HUD a soldier might have built into a helmet or goggles. But that’s not a metaphor: it’s an extension of the immersive experience. It’s literal. It’s realism.
Where does this leave us? Skeumorphism is an option. Metaphor is an option. But good UI can be much more efficient, and much easier to learn and use without metaphor, because if there is no metaphor, the UI doesn’t require that the metaphor hold its connection to the real world. The connection doesn’t break down, because there isn’t one. An immersive experience builds the best connection between the user and software, but even in immersive worlds we need UI elements that are not representational and are not metaphorical.