Designing for the Edge Cases

I’ve been thinking a lot about edge cases recently. Not so much along the lines of “we don’t need to worry about that because its an ‘edge case’” but instead the small details that pop up when you least expect them.

There are several examples I can think of when I think of edge case details in interface design:

1) Starting up OS X for the first time: the very first time you start up your mac (or freshly install the OS) you go through a series of setup screens. The screens themselves are designed very well and the animations (including the intro movie clip) make for a nice start up experience. Recently Apple has added a new touch to this start up process, you now get a prompt to take your photo which applications like iChat and Address Book take advantage of. Its a very minor thing, but its the sort of experience that ends up being memorable for users. It stands out for many as part of their “mac experience.” Its been pretty well documented that Jobs cares quite a bit about the user’s impression when booting their mac for the first time.

2) Another good example of an edge case UI decision is the “Blank Slate”. This is a term that 37signals made famous in the book Getting Real and on their blog Signal vs. Noise. It refers to the initial state of a web application before you put in any data. In the case of Basecamp when you initially come to-do section that isn’t populated with to-dos you have some helpful information and maybe some some sample to-dos just to show you how it might look populated. This has started to become the norm for most web applications. I love the idea that someone thought ahead and instead of making the page blank and bare they were most interested in helping you out, showing you how to use their app by example.

3) The last example is a detail that you can find in Shaun Inman’s mint. Its not a functional detail, its more of an easter egg, but I think it’s just as valid for this discussion. When you hit the keys “up, up, down, down, left, right, left, right, b, a” inside of mint you get a nice easter egg of stan. Obviously Shaun placed this in as as a joke or just for his own enjoyment, but nonetheless he made a decision for that detail. In mint’s case it no doubt helped create some buzz within the blog community and possibly even led to more sales through general awareness.

I hope the above examples demonstrate that thinking about the smallest details do matter when creating interfaces. They can help users better understand how to use your application, like in the case of basecamp or they simply delight the user as in the cases of Apple and Mint.

These are just a few examples I would love to get some feedback on other examples that you can think of.