ThinkFlood Blog

If you have been following along as I unveil my crazed delusions regarding usability, you may have been wondering when I would get around to this principle. It seems that many people place familiarity on the top of the pile. This is a natural thing to do, of course — if we are already accustomed to a particular interface or behavior, why not replicate it? At the very least, it can’t be worse than the original, right?

Well, yes and no. Before I launch into criticism of the idea of familiarity, a disclaimer: of course familiarity is important, and it is an effective way to design interfaces. Metaphors (like the desktop or the trash can/recycle bin), real world controls (like buttons and sliders), and familiar images, colors, and sounds all have a major role to play in intuitive interface design. We humans think associatively, so it is relatively easy for us to learn new things when there are familiar components for us to latch onto. Familiarity as a design principle absolutely deserves a spot on my list.

Now for the diatribe.

There are a lot of places where familiarity breaks down, and one of them is over-reliance upon it. For example, a friend of mine in Illinois once told me how he had watched someone demonstrate a new graphical shell that employed a physics engine. In this brave new world, everything reacted just as you would expect from your experience in real life. This sounds great – until you actually use it. The issue was that it was too realistic. So, when you are trying to move that folder with 30GB of files inside it takes twenty seconds to drag it across the screen because it is supposed to “feel heavy.” I have to wonder why someone would want to build frustration and tedium into an application.

One of the great things about the virtual world is that we do not have to deal with physical constraints. It might seem that this would go without saying, but I see evidence of misguided design everywhere. For example, at the moment everyone seems to love transparency and lighting effects – “reflections are the new drop shadows,” some say. But I have to wonder why it makes any sense to imitate glare on a button face, when most people staring at a computer screen all day do what they can to eliminate glare because it makes things hard to read. In fact, virtual glare is worse than the real thing, because no matter how we try, we can’t block it by adjusting monitor position or closing the blinds. Let’s not through out good graphical design (including high contrast between text and background) just to make things look spiffy.

Another danger with familiarity is that not everyone has the same experience — the old subjectivity argument that I like to bring out. Here’s one that may surprise you. I would bet that just about everyone who has used a computer in the last twenty years is familiar with the cut/copy/paste metaphor. After all, these three functions alone made word processing a killer app. But how many people understand the genesis of the familiar scissors (cut) and glue (paste) icons floating out there on the toolbar in their word processors? As it turns out, people that have come of age since the arrival of the word processor just do not have the experience of cut and paste typewriter correction. Is this an effective metaphor for them? Not really. But they understand it anyway because they grew up with computers (i.e., consistency probably matters more than familiarity here — but I’m getting ahead of myself by a couple of principles now).

While I caution moderation with the use of metaphors, colors, and so forth, there is a type of familiarity that I find particularly lacking — that of physical interface familiarity. I am not talking about representations of the real world, but rather real world interfaces. For example, the keyboard and mouse are unnatural – we do not control anything with these interfaces other than computers. The keyboard is a 19th century replacement for speech — with the QWERTY layout intentionally made inefficient so as to slow down typists to prevent the keys from jamming together at the print head. And the mouse is a sorry replacement for those universal pointing and manipulating devices, fingers. Here we have technological constraints dictating the physical interface, rather than design ideals. Of course there have been many attempts (most failing pretty miserably) at reliable voice and handwriting recognition. But technology improves over time. I think a lot of the interest around the iPhone stems from its bold reintroduction of the finger as the primary pointing and manipulation device. Technology analysts all seem to be talking about how touch screens are on the verge of explosive growth. Personally, I hope they are right.

There are a lot of other physical interfaces that we have left to explore. Some applications today do alright with sound and visual cues as feedback mechanisms, but there are other things. Eye motion, facial expressions, maybe even behavioral patterns. Personally I would be thrilled if those people developing operating system kernels (though they be far removed from interface design) were to recognize that when I start clicking frantically they should give more CPU to the process I am trying to manipulate and put whatever else is happening on hold for a minute.

To sum up, familiarity is a great idea in interface design. It comes a little later on the list because it is subjective (the prior six principles are not subjective, and by their more universal applicability, deserve a more important position), and because it is more helpful to the novice than the expert. When dealing with abstract familiarities (such as metaphors), we need to exercise some caution to make sure that we are not violating other usability principles. But when it comes to physical interfaces, we could do well with a lot more “familiarity” than we see today.