Before starting application development, analyze and define the requirements, scope, and
functionality of the application to ensure efficient functionality and a smooth user
experience. Design the application for a single purpose and analyze how it can best serve
its users. Mobile devices have been designed for use when mobile. Keep the characteristics
of mobile devices in mind when you create applications for them.
The following guidelines help you design and develop usable applications for mobile devices
with varying characteristics, such as screen size and support for input methods:
\list
\o Know your users
Find out who will use the application, what they will use it for,
and which mobile devices they have. Then design the application to fit a specific context
of use.
\o Design for small screens
The screen size of mobile devices is significantly smaller
than that available on desktop devices. Carefully consider what is the most relevant
content to present on the application UI, as it might not be reasonable to try and fit as
much content into the screen as you might have in a desktop application.
\o Design for multiple screen sizes
Relate the position and size of each control to the
dimensions of the display. This enables the same set of information to be presented on the
screen in all resolutions; higher resolution devices just display finer graphics.
\o Design for changing screen orientation
Some devices support screen rotation. On these
devices, applications can be displayed in portrait or landscape orientation. Account for
orientation and dynamically adjust the display when the screen is rotated.
\o Design intuitive ways of moving within applications
Mobile devices lack a mouse and
full-size keyboard, so users must use the touch screen or five way navigation pad to move within
applications. In addition, many users control the devices with one hand. To create an optimized user
experience, allow users to access information with one click; do not make them scroll and type.
\o Design for limited input methods
Applications collect information from users on the task
at hand. In addition to touch screen input, some devices contain physical keys such
as a five way navigation pad, a keypad, and a keyboard. Users enter information by using screen
controls, such as lists, check boxes, radio buttons, and text fields.
\o Keep response times short
Latency can cause delays in user interaction. If users perceive
an application as being slow, they are likely to get frustrated and stop using it.
\o Save battery time
Mobile devices are not constantly connected to a power source but run on
battery power. Optimize power consumption to keep the total consumption at an acceptable
level and to prevent users from running out of battery time.
\o Consider network issues
If users do not have a flat-rate data plan or WLAN support, mobile
network connections cost them money. Also, when users move around with the devices, the networks
available for connections constantly change.
\o Remember the processing limits of the device
The memory available on devices is limited
and you should use it carefully. Although all mobile devices have common functionality,
each device is individual in terms of both the resources available and extra features.
Therefore, you must consider the constraints of all the target devices.
\endlist
For more information about user experience techniques for mobile devices, see the
\l{http://library.forum.nokia.com/topic/Design_and_User_Experience_Library/GUID-A8DF3EB8-E97C-4DA0-95F6-F464ECC995BC_cover.html}{Design and User Experience Library}
