Effects of Depth Layer Switching between an Optical See-Through Head-Mounted Display and a Body-Proximate Display
This addresses a design problem for developers of multi-display AR systems, but it is incremental as it quantifies an existing issue rather than proposing a solution.
The study quantified the performance cost of switching depth layers between an optical see-through head-mounted display and a body-proximate display, finding that task completion time increased by about 50% and error rate by about 100% compared to single-layer visual search.
Optical see-through head-mounted displays (OST HMDs) typically display virtual content at a fixed focal distance while users need to integrate this information with real-world information at different depth layers. This problem is pronounced in body-proximate multi-display systems, such as when an OST HMD is combined with a smartphone or smartwatch. While such joint systems open up a new design space, they also reduce users' ability to integrate visual information. We quantify this cost by presenting the results of an experiment (n=24) that evaluates human performance in a visual search task across an OST HMD and a body-proximate display at 30 cm. The results reveal that task completion time increases significantly by approximately 50 % and the error rate increases significantly by approximately 100 % compared to visual search on a single depth layer. These results highlight a design trade-off when designing joint OST HMD-body proximate display systems.