Estimating the Effects of Encumbrance and Walking on Mixed Reality Interaction

This paper investigates the effects of two situational impairments—encumbrance (i.e., carrying a heavy object) and walking—on interaction performance in canonical mixed reality tasks. We built Bayesian regression models of movement time, pointing offset, error rate, and throughput for target acquisition task, and throughput, UER, and CER for text entry task to estimate these effects. Our results indicate that 1.0 kg encumbrance increases selection movement time by 28%, decreases text entry throughput by 17%, and increase UER by 50%, but does not affect pointing offset. Walking led to a 63% increase in ray-cast movement time and a 51% reduction in text entry throughput. It also increased selection pointing offset by 16%, ray-cast pointing offset by 17%, and error rate by 8.4%. The interaction effect on 1.0 kg encumbrance and walking resulted in a 112% increase in ray-cast movement time. Our findings enhance the understanding of the effects of encumbrance and walking on mixed reality interaction, and contribute towards accumulating knowledge of situational impairments research in mixed reality.