How did the allies hide a compass in a button during the Second World War? They designed it so that you had to screw the button clockwise to open it.
The UK’s experts in deception reasoned that the enemy would never think to turn something the wrong way to unscrew it. As I read about this in Ben Macintyre’s book Operation Mincemeat last week, I tried to imagine unscrewing something the wrong way, and it just felt wrong, whether it was a screw holding together furniture or a jam jar lid.
We become accustomed to simple things working in the same way, and would get confused if they didn’t.
Things that meet our expectations are often described as intuitive, simply because we’ve learned to use them so well that we don’t have to think about them.
For example, many of us can type now without having to think about where particular keys are on the keyboard. That’s not because the keys are laid out in a particularly logical fashion: it’s because we’ve practised and reached a state where our subconscious mind can do much of the work, and it’s because every keyboard uses the same arrangement of keys.
Similarly, experienced drivers can operate a vehicle without thinking about the pedals or other controls, in part because all cars work more or less the same way.
If you want your app to be intuitive, you need to make sure people can use the experience they have from elsewhere, including other apps.
People know what buttons or links are, and how to fill in forms on the screen. They understand that touch interfaces usually require them to tap things to select them, or drag them to move them. The more similar you can make your interface to other games, the easier it will be for players to concentrate on the content of your games instead of having to work out where the controls are or whether something on screen is a label or a button.
There are a few resources to help with this. If you’re developing apps for Windows, Microsoft publishes its Windows User Experience Interaction Guidelines. They range from technical points on things like optimal screen resolutions through to usability tips (‘Use ordinary, conversational terms when you can’, ‘Never require users to click an object to determine if it is clickable’).
There’s advice on writing errors too: Windows doesn’t ‘fail’ or have ‘errors’; it has ‘problems’. The top tips for designing a great user experience are valuable, whichever platform you use.
There’s also an Application Design guide for MeeGo, the Linux-based operating system that provides a single platform across tablets, smart phones, netbooks and smart TV.
The guidelines include details of gestures commonly used in touch-based MeeGo apps, and tips for handling different screen orientations. If you’re not familiar with MeeGo, the guide also provides a good overview of what’s different about it.
As a game designer, you might think that user interface conventions don’t apply, but most games have utility-type features, such as scoreboards and settings.
The easier you can make it to navigate your app, the quicker people can get into your game. Macintyre’s book is about the creativity that went into tricking the enemy in war time, but it doesn’t take much to confuse people.
Follow the guidelines for your preferred operating system to make sure any confusion you create is the result of carefully crafted in-game puzzles, and is not caused by a frustrating user experience.
Sell your Windows and MeeGo apps through the Intel AppUp developer program.