Mobile phone-specified usability studies were conducted. First, comparion of user interfaces and inteaction flows of several competitive mobile phones was done in a laboratory condition. Then, more natural user observations such as shadow tracking and self-recording (with camera-attached glasses) were followed to better understand their real world based contexts of use. Finally, a concept of "interaction map" was suggested to combine all user data from different observation methods to analyze and solve users' problems and needs from integrative perspectives.

Methods: User observation, Task analysis, Shadow tracking, Self diary