Because devices typically have smaller displays and limited input mechanisms, it is very difficult to convey what mode the product is in, and often requires significant navigational work to change modes.

• 由于手持设备的显示屏通常都较小，输入方式也相对有限。 所以很难像模式化的产品那样表现，要改变这些模式则通常需要非常费时费力的导航工作。