Icons come in 666 flavors. Icons on products, in architecture, in computers, in lists, on buttons, for the Web and for apps, for iOS and Android. Icons on toolbars, labelled and unlabelled, styled and standardized, colored or monochrome, in fonts, PNGs or as SVGs…

There are tons of free and paid icon collections, vector and pixel, 2D and 3D, and if you want to write rules on how to deal with them all you’d need to write a big icon cookbook. There are so many damn icons that the devil might trick you into solving all of the world’s design problems with them.

Watch out though: If you answer every design question with “Icon!”, one day Don Norman may knock on your door and, when you open it, he will look deep into your eyes and say:

Inscrutable icons litter the face of the devices even though the research community has long demonstrated that people cannot remember the meaning of more than a small number of icons […] Who can remember what each icon means? Not me.

In this case, Don Norman is lecturing his former employer Apple. Some outstanding examples of Apple’s iconitis can be found in iTunes, Mail and the iOS dashboard.

The iTunes icons gained Icon Bogeyman rock star status on Twitter. The Apple Mail customization screen offers a nice sample too: How many icons from this choice of Apple Mail for OS X can you identify without labels?

What does this tell us? Not much, except that icons save space and great icons look fresh. But unless you have designed and assigned them yourself, their clarity is suspect. An icon can represent a thousand different words, and that is precisely the problem. Anything with a thousand possible meanings needs a lot of context to become unambiguous. Here is the same choice of icons with labels:

Labels explain icons. Adding labels improves usability. Which is why some cold-hearted people claim “labels are the best icons”. Logically there can be no confusion if you use the right labels. So why don’t we just use labels and drop icons altogether?

Functionally, a “label-only” design is as clear as day (if the IAs have done their job), but something unsettling happens if you pull all the graphics from a graphical user interface. The temperature drops to 0° Kelvin. It doesn’t look crisp and fun anymore. A design positivist may not care about crisp and fun. Every other human being does. We tested this assumption in iA Writer. The feedback we got during the period we eliminated all icons was a resounding “Don’t!”

Maybe the questions we should ask are not “icon or no icon”, “label or no label”, but: How and when do we use icons only, labels only? When do we use icons plus labels and when shouldn’t we? Let’s see…