I was just looking at some impressive screenshots and videos of potential user interface interactions for Microsoft’s Courier, a double-page concept tablet with both touch and pen-based input geared towards e-books and creative/productivity applications.
It raised some thoughts for me regarding interface discoverability. When approaching computer interface design, whether for Web sites or applications, it’s not enough to create something that looks cool and works well. You have to make your experience discoverable. If a certain gesture across the screen activates new functionality, how will users know that? If a click or a swipe on an object makes it do something different, or a menu pops up when holding a device a certain way, or data is transformed by moving a pointer or pen around it, how on earth will anyone find that out? Will users be trained ahead of time to use your software or device effectively? Of course not! I know people that have used computers for years and don’t even realize you can use Command/Ctrl-C for copy and Command/Ctrl-V for paste. It’s unrealistic to think that people will somehow figure out how to do something that isn’t extremely obvious and begging for attention.
I’m not dumping on Microsoft here. Apple is not immune from such criticism either. How many people know you can shake your iPhone to undo something? I forget all the time. And it took me forever to figure out how to stop my home screen icons from doing the shaking dance when I was moving app icons around. Now I know I need to press the home button again, but, geez, how was I supposed to know that? Also, why do most apps have their settings available from within the app itself, but meanwhile the system-wide Settings app also has app-specific settings? Two locations…redundant. I seriously doubt most people will think to look in Settings for something specific to an individual app.
I remember a long time ago, I was developing an e-commerce site for a maker of Celtic crafts and clipart, and for the navigational element at the top of each page that would bring up the customer’s shopping cart, I created a very simple cart icon. It looked exactly like a shopping cart. Guess what? Nobody knew they needed to click on it to get to their shopping cart. So I added the text “Shopping Cart” next to the icon. That worked.
I learned a valuable lesson that day. Just because YOU know how something works that you’ve just designed, doesn’t mean anyone else is going to know how it works. Make it discoverable. Make it obvious. Then make it more obvious. Assuming users need to learn new tricks in order to work with your interface is debatable at best and hubris at worst. The more you can spell out in simple visual ways (and even, gasp!, help text) how something is to be operated, the better your UI will be.