SituFont: A Just-in-Time Adaptive Intervention System for Enhancing Mobile Readability in Situational Visual Impairments

TL;DR

SituFont is a context-aware, adaptive typography system that dynamically adjusts text presentation on smartphones to improve readability during situational visual impairments, based on real-time sensor data and human feedback.

Contribution

This paper introduces SituFont, a novel adaptive typography system that personalizes text display for mobile readability during visual impairments using real-time contextual sensing and human-in-the-loop adjustments.

Findings

SituFont improves reading efficiency in simulated SVI scenarios.

Participants experienced reduced workload with SituFont compared to manual adjustments.

The system effectively adapts to environmental and personal factors affecting readability.

Abstract

Situational visual impairments (SVIs) hinder mobile readability, causing discomfort and limiting information access. Building on prior work in adaptive typography and accessibility, this paper presents SituFont, a context-aware and human-in-the-loop adaptive typography adjustment approach that enhances smartphone mobile readability by dynamically adjusting font parameters based on real-time contextual changes. Using smartphone sensors and a human-in-the-loop approach, SituFont personalizes text presentation to accommodate personal factors (e.g., fatigue, distraction) and environmental conditions (e.g., lighting, motion, location). To inform its design, we conducted formative interviews (N=15) to identify key SVI factors and controlled experiments (N=18) to quantify their impact on optimal text parameters. A comparative user study (N=12) across eight simulated SVI scenarios demonstrated SituFont's effectiveness in improving smartphone mobile readability in terms of improved efficiency and reduced workload compared with a non-trivial manual adjustment baseline.