On every PC laptop made in the past 5+ (10+ ?) years, many of the “F1” (F2, F3, …) keys, and sometimes some of the other keys (the arrow keys in particular) serve two purposes. When pressed normally, they act as their respective key — F1 acts as F1, etc. However, when pressed in conjunction with the “Fn” key, they perform a special function indicated by an icon on the key. Usually both the icon and the label on the Fn key will be blue (whereas the other key labels are white.) For instance:

Today, one of my professors tried to hook up his laptop to the projector and was befuddled when it didn’t work. As soon as I saw him struggling, I knew that the problem was that he had to turn on the external video out. PC laptops typically have three display output modes: internal LCD only, external (VGA, or sometimes DVI these days) connector only, or both internal and external simultaneously. In order to change the mode, one typically has to either use the Fn function of one of the F keys (typically F5, F6, or F7.) Sometimes it can also be done through some buried option in the Display control panel.

The reason I knew that this was a problem is because almost every single professor who I’ve seen hook a laptop up to a projector has had to do this and had no idea what they had to do or how they were supposed to do it. The notion of hitting Fn in conjunction with some other key didn’t even seem to occur to them. Here’s something that’s a common thing to need to do, and laptop designers have tried to come up with a design that affords doing it (Fn is always next to Ctrl, so it should be natural to interpret it as a modifier key, and the color labels reinforce hitting Fn in conjunction with specific keys), but their design has failed, even after it’s been around for so many years and people have had a chance to get accustomed to it. Why doesn’t their design work? (And why do they keep using it?) (more…)