One of the most used framework for representing the research content and dimensions is the activity theory (AT), which uses activity as a unit for analyzing human practices (Bakhurst, 2009). Recently, several researchers have used the AT as a theoretical basis for analyzing mobile learning studies (e.g., Frohberg et al., 2009; Sharples, Taylor, & Vavoula, 2007) or for
designing mobile learning scenarios (e.g., Zurita & Nussbaum, 2007). This study used six major components of AT to select moderator variables and analyze mobile learning: (a) Subjects: which involve all the people who may be involved in learning curriculums through mobile devices, such as students of different age levels or teachers of different levels of teaching
expertise. (b) Objects (or objectives) of the mobile learning, which focus on the goal such as acquiring cognitive skills or enhancing learning motivation through mobile devices. (c) Tools/instruments in the mobile learning, which may be artifacts or learning resources (e.g., tutors). (d) Rules/control for the activity, which are norms or regulations that circumscribe the mobile activities, such as the procedure in teaching scenarios designed for the learning pace or styles designated. (e) Context of the activity, which refers to the physical (e.g., classroom or museum) or social environments for conducting mobile learning. (f) Communication/interaction, which refers to the method of interaction between users and mobile technologies (such as the process teachers' adaption to mobile devices) or the communications styles among learners.