Effects of spatial constraints and ages on children?s upper limb performance in mid-air gesture interaction

Through two controlled experiments, including a pie menu study and a target acquisition study, this paper investigates children's performance on mid-air gesture interactions in different spatial constraints (i.e., in different orientations/distances), as well as the age effect on such interaction scenarios. The first experiment recorded children's speeds and accuracies following certain directions under menus with different numbers of items, while the second evaluated the speed-accuracy trade-off (SAT) of children's arm movements. We also compared performance differences between two age-related groups (i.e., 6-8 years old and 9-12 years old). Based on these experiments, we propose an improved design for UI menus based on mid-air gesture interaction for children. The improved design provides suggestions for setting appropriate directions and difficulty indexes, which makes it much easier and quicker for children to use the menus with mid-air interaction.