Exploring the usability of augmented reality interaction techniques during children's early elementary-school years

Augmented reality (AR) has been shown to have measurable benefits in enriching children's lives, by advancing education through in-situ 3D visualizations, providing entertainment through whole-body interaction, and enhancing physical & cognitive rehabilitation through motivational engagement. Although such experiences were typically confined to desktop computers, the increasing popularity of mobile devices is expected to make AR accessible to large amount of children. In order to realize these benefits, technology designers need to create experiences that are usable by children. Handheld AR interfaces are different from more traditional interfaces, by being small portable windows into physical spaces augmented with digital content, and their use may require users to employ more complex motor and cognitive skills than compared to traditional interfaces. Due to the novelty of handheld AR technology, there are no standard interaction techniques for handheld AR, and little is known about children's ability to use these interfaces. In the current research, I address the following questions: How does children’s age relate to performance and usability issues in handheld-AR? How do different handheld-AR interaction techniques compare, in terms of performance and usability issues encountered by children? And, what types of usability issues are experienced by children in handheld-AR? In order to address these questions, I first constructed several commercial and prototype educational AR games for young children and studied their educational potential, as well as children's ability to use these games. I contributed analyses of how augmented reality can be applied in educational contexts. Further, I generated a usability framework that organizes the usability issues observed in my studies and in existing literature on AR systems for children, discusses relationships between developmental psychology literature and children's AR usability, and provides guidelines for designing AR for children. Finally, I performed a systematic study of children 5-10 years old using handheld augmented reality, as they played a smartphone-based AR game using two AR interaction techniques (finger-based vs. crosshair-based selection) under two movement conditions (tunnels vs. no tunnels). Children's performance and usability problems were analyzed through quantitative and qualitative methods. This research identifies complex relationships between usability metrics and children’s age across the elementary-school years (e.g., significant changes occurring around 7 years, in children's ability select items quickly while reorienting their body in a 3D space; significant increase in poor postures in older children; age-invariant frequency of phone dropping; etc.). This research also identifies a variety of usability issues encountered by children of different ages (e.g., the detrimental effects that previous exposure to non-AR technology has on children's ability to work with AR tracking technology; or, the variety of ways in which children lose tracking while playing AR games). The research identifies links to cognitive and physical developmental skills that underlie AR performance (e.g., crosshair-based selection employs skills related to visuomotor precision and spatial relations, while finger-based selection employs skills used in block building activities). Furthermore, gender differences in technology exposure are identified, along with effects of practice during short gameplay sessions. This research concludes with a set of guidelines for designing handheld AR technology for children in the 5-10 year old range, along with a set of directions for future work, involving applications of child usability to upcoming AR technologies, and improvements to the research methods in studying AR for children.Ph.D