Guidelines for Mobile Interface Design
The interface design is a critical factor for the success of any Application or even a Mobile Device. Designing any user interface is about creating a balance between "demand and supply". Well I am certainly not talking about economics, its about what all user is looking for and what all you can provide with all the restriction a developer face. To understand the user needs and presenting it in the best way is what the challenge here. We all know how some time a simple page with a text input field creates a revolution.
The now proposed guidelines seek to improve the user experience and apply to the majority of the applications for mobile devices.
One of the most important aspects to be consider before starting with Interface Design is to see how user is interacting with the device. Following are the technique currently in use:
Key Based Input
Interacting via physical keys have many restrictions but till now they proved to be the most efficient technique. Different key based techniques are:
It is the most commonly used type of key board.
Half Qwerty Keypad
Touch Based Input
Interface design for touch based devices can be more versatile. Since touch is a new thing in mobiles, currently lots of possibilities are looked into and lots of creativity can be seen. There are few ways touch screens can be accessed :
Enable shortcuts for frequently used functions
Time is a critical factor for the users that generally need “Just in time” information in the mobile context. That is why, reducing the amount of steps required for the user to perform frequent operations facilitates his adaptation to the application device.
Maintain the used informed of its actions
Always maintain the user informed about what is happening in the application.. It can be done using sounds, dialogs, messages, etc.
Follow the device’s interface patternUsing the system’s native interface components reduces the learning curve of the user regarding the application once the interface will be similar to others that he is already used to.
It's a subset of the last section. It is important to pay attention to the menu positioning on the screen. For example, in the Nokia devices in general have the application trigger located on the left side of the screen while on the right is located the trigger used to cancel an action. The same positioning is used for YES/NO actions.
 - G ONG, J., AND TARASEWICH, P. 2004. Guidelines for handheld device interface design. In Proceedings of DSI 2004.