Do size and structure matter to mobile users? An empirical study of the effects of screen size, information structure, and task complexity on user activities with standard web phones

The small screens of mobile Internet devices, combined with the increasing complexity of mobile tasks, create a serious obstacle to usability in the mobile Internet. One way to circumvent the obstacle is to organize an information structure with efficient depth/breadth trade-offs. A controlled lab experiment was conducted to investigate how screen size and information structure affect user behaviours and perceptions. The moderating effects of task complexity on the relationship between screen size/ information structure and user navigation/perceptions were also investigated. Study results indicate that both information structure and screen size significantly affect the navigation behaviour and perceptions of mobile Internet users. Task complexity was also found to heighten the influence of information structure on user behaviour and perceptions. The paper ends with a discussion of theoretical and practical implications, among them a key implication for mobile Internet businesses: for corporate intranet systems as well as m-commerce transaction systems, the horizontal depth of information structures should be adapted to task complexity and anticipated screen size.