Quantifying the Cost of Manual Navigation: A Comparison of Gesture-Based Magnification versus Direct Access Reading in Digital Layout-based Documents
For designers of digital documents and accessibility tools, this work demonstrates that direct-access reading via large-print editions significantly outperforms standard gesture-based navigation, highlighting the need for automated layout adaptation.
This study quantifies the cost of manual navigation (pinch and zoom) versus direct structural access in layout-based digital documents, finding that large-print editions improve reading speed by 18% and target location speed by 30%, restore natural reading strategies, and reduce workload compared to gesture-based magnification.
Understanding how diverse audiences engage with structured media is critical to ensure a consistent quality of experience. In this context, we quantify the behavioral and performance cost of manual navigation (e.g., pinch and zoom) versus direct structural access in layout-based digital documents. We specifically investigate newspaper reading when visual access to structural cues (headlines as entry points) is constrained. Participants completed two tasks-reading all headlines aloud and locating target articles-under two conditions: (1) original edition with gesture-based magnification (pan and zoom), which is the industry standard for digital documents, and (2) large-print edition supporting direct-access reading. We collected performance measures (success ratio and completion time), behavioral integrity through reading path analysis, alongside perceived workload and preferences (NASA-TLX). Results from linear mixed-effects models show that the large-print condition yielded not only better performance than gesture-based magnification (18% improvement in reading speed, 30% improvement in speed to locate a target), but more importantly, restored the natural reading strategy that gesture-based magnification interaction disrupts. Readers also reported lower workload and higher preference. These findings highlight the importance of developing automated methods for generating large-print editions, where layout adaptation complements font scaling to support accessibility and quality of experience.