Mobile Design 101

To use an MP3 player to listen to a song would you rather press 'Play' or 'Ok'?

While many mobile phones tout themselves as MP3 players very few provide an obvious dedicated 'Play' button to listen to music. In a world where convergence is king this damaging oversight seems down right embarrassing. It just doesn't seem easy to listen to music on a mobile phone. If phones are ever to have a hope of one upping traditional MP3 players then it's time to get designers back to the drawing boards.

Designers face a clash between two seemingly conflicting interface design heuristics. An interface should be as simple as possible, of which Google's homepage is the classic example. An interface should always provide controls to do what you want as quickly as possible, everything should be just a click away, you shouldn't have to think about it. Of course current cell phones can do a lot. To have everything close at hand would be impossible without breaking the first heuristic by introducing a huge number of new controls. Balancing the two has become a problem of providing relevant generic controls. We can all recall a horror story of trying to set a car clock.

Mobile phones provide functionality above and beyond what typical MP3 players are expected to do. Though most phones have some space for additional buttons, they can only be added at the risk of overwhelming users. Instead phones tend to err towards simplicity in that they provide a handful of standard controls which cater to the lowest common denominator of functionality. An 'Ok' button is useful in many circumstances so it is provided as a one size fits all method of addressing most actions. MP3 players, cameras and all manners of devices have controls specifically designed to make them easy to use. On an MP3 Player, an 'Ok' button is far less useful than a 'Play' button in this regard. On a MP3 phone how can designers provide controls both for media and call functionality without making the device too complex?

Samsung's F300 is an interesting answer. Look at the phone from one side and it appears to be a normal cellphone. Flip it over and you'll be surprised. The phone has no back. Instead the other side bears its own screen and dedicated media controls. From this side it could pass as an MP3 player. Regardless of whether the F300 technically achieves its goals or not, from a design stand point its novel construction should raise a few eyebrows. Samsung has added dedicated MP3 controls without adding complexity. Using it, you will only ever be looking at one set of controls at a time, the other controls are physically separated and out of sight. If you want to make a call use the phone side. If you want to use media use the MP3 side. Separating the functionality like this has also allowed Samsung to apply a third interface design heuristic which is simply to stick to what people know. People understand MP3 players. People understand mobile phones. By echoing the traditional image of an MP3 player, people viewing the F300 will immediately associate it with their past experiences with MP3 players. The learning curve of using the device is less because people can draw on past experiences with other similarly designed MP3 players. Finally we can just press 'Play'.

In a similar vein, Sony Ericsson's Cyber-Shot K800i combines a camera with a cell phone. Typically out of sight, the 'Zoom' and 'Take Picture' buttons are placed along the side of the phone. When the phone is held like a camera your fingers are instinctively drawn to them out of old habit from using standard cameras.

For mobile convergence to be successful phones must provide the same level of specific control with the same ease of use as the devices they are trying to emulate. The generic control standard on phones today cannot do this. In the in-term before the arrival of polymorphic displays it is possible to achieve this through innovative placement of additional controls. By taking lessons about control placement from traditional MP3 players and cameras, designers can make using multi-functional mobile phones less of a headache for everyone.

-jb