You'd think that double clicking is pretty damn easy right? Chances are if you're reading this site, you've been doing it for at least ten years, and if you're my age, their's a fair chance you've been double clicking reliably a lot longer than you've been able to reliably catch a tennis ball. Hell, I know a 3 year-old kid who can't walk reliably. But he's a fair hand at Quake - he's fragged me. (Not that this is a particularly notable or unique achievement).

Yet double clicking is in fact not all that easy. Even the name is a bad user interface decision. A “click” is a sound. Things click - you don't click them. Asking someone to double click the mouse is as intuitive as asking them to double bang their mouse, or to double *whump* their mouse. This all struck me with blinding force when I trying to to help my father use a PC.

The parental computing saga began back in 1984, when he purchased an Apple Macintosh. It's sat unused on his desk for the last 18 years. It still runs - why wouldn't it? It's in pristine condition after all. Now, as retirement approaches, he's decided it's time to get with the times and use this “internet”. And I am his teacher. And I'm learning just as much as him.

The problems began when we tried to start the computer up. From watching 40 years of television, the idea that when you turn off the screen you have turned off the computer is pretty well ingrained. And vice versa - to turn on the computer you turn on the screen. But this was a mere molehill compared to the next mountain: Clicking on the “OK” button at the Windows Logon dialog. First we had the whole issue of what a “click” was - you “depress the left mouse button over the button, and then release the left mouse button while still over the button”. Surprisingly, what this means is not immediately obvious to someone who has never used a computer before. Next comes the issue of controlling the mouse sufficiently to actually position it over the OK button. And the fact that my dad is left handed. And so the left mouse button is, in his mind, what we would all - even the left handers amongst us - call the right mouse button. After all, the right mouse button is the one you click with your middle finger… which makes it the left mouse button if your using the mouse left handed. As confusing a series of events to experience as it is to try and describe!

But even that was nothing to the epic of the double click! Together, we spent half an hour trying to launch Internet Explorer. Aiming was no problem. But holding the mouse still enough and clicking the left (right) button twice in a row and fast enough was. In the end, we managed by carefully positioning the mouse cursor over the icon, using the right hand to hold it in a vice like grip and the left hand to poke at the left (right) button. This worked about 50% of the time.

After an hour, we retired from the field of battle, tired but successful. Internet Explorer was successfully launched not once, but twice. The computer, with the aid of copious notes and a reminder or two from me, was shut down.

The conclusion from all this? Names are important. Metaphors are important. Metaphors must be obvious. You and I share a computing vocabulary that is not intuitive. Not in the slightest. So bear it in mind when your designing user interfaces - especially the way you phrase the messages you send to users. My Dad doesn't know what a “click” is, and I don't know what Modem Error #623 is. ”(A)bort (R)etry (I)'m An Idiot” is not the feeling you want to elicit in your users.

And as a finale: The moral of the story? Nothing particularly revolutionary. Scott Adams said it best: Most people are dumb most of the time, ourselves included. So design for a dumbed down you, and you may just avoid pissing off your users. (There's a deeper moral in there too - something about building the metaphorical foundations - but that's a topic for another day!)