Another effect of mobile usage that could be strengthened is the expansion of measurements of dependent variables. Most of the studies in our research currently still placed the interests on achievement in content knowledge (e.g., Liu, 2009; Wang & Wu, 2011), and methods for measuring higher-level skills were scarce. Mobile devices were expected to encourage innovation in education and increase high-level abilities (Frohberg et al., 2009; Sung, Chang, & Yang, 2015; Zucker & Light, 2009). Yet most of the research collected for this study focused on increasing content learning, and even though the designed educational activities involve explorative, communication, and cooperative skills, the dependent variables had
almost no connection with these skills. For example, in the database of our research, only 5 of the 9 experimental/quasi experimental studies explored the interactive behaviors of students during their mobile learning; furthermore, none of the 24
inquiry-oriented learning recorded and investigated process-related skills such as hypothesis-formation and hypothesistesting. Therefore, including dependent variables besides content knowledgedsuch as problem-solving, critical thinking, interactive communication, or creative innovation skillsdin the measurements will make the persuasiveness of the educational effects of mobile devices much more convincing.