AReading with Smartphones: Understanding the Trade-offs between Enhanced Legibility and Display Switching Costs in Hybrid AR Interfaces

This research investigates the use of hybrid user interfaces to enhance text readability in augmented reality (AR) by combining optical see-through head-mounted displays with smartphones. While this integration can improve information legibility, it may also introduce display switching side effects. The extent to which these side effects hinder user experience and when the benefits outweigh drawbacks remain unclear. To address this gap, we conducted an empirical study (N=24) to evaluate how hybrid user interfaces affect AR reading tasks across different content distances, which induce varying levels of display switching. Our findings show that hybrid user interfaces offer significant readability benefits compared to using the HMD only, reducing mental and physical demands when reading text linked to content at closer distances. However, as the distance between displays increases, the compensatory behaviors users adopt to manage increased switching costs negate these benefits, making hybrid user interfaces less effective. Based on these findings, we suggest (1) using smartphones as supplementary displays for text in reading-intensive tasks, (2) implementing adaptive display positioning to minimize switching overhead in such scenarios, and (3) adjusting the smartphone’s role based on content distance for less intensive reading tasks. These insights provide guidance for optimizing smartphone integration in hybrid interfaces and enhancing AR systems for reading applications.