Improving Low-Vision Chart Accessibility via On-Cursor Visual Context

TL;DR

This paper introduces two pointer-based interaction methods, Dynamic Context and Mini-map, to improve chart accessibility for Low-Vision Individuals by providing critical visual context, enhancing understanding and usability.

Contribution

It proposes novel interaction techniques tailored for Low-Vision Individuals to access chart context, supported by empirical evaluation and design insights.

Findings

Dynamic Context improved access and usability but increased visual load.

Mini-map enhanced spatial understanding but was less preferred.

Both methods offer valuable benefits for LVI chart exploration.

Abstract

Despite widespread use, charts remain largely inaccessible for Low-Vision Individuals (LVI). Reading charts requires viewing data points within a global context, which is difficult for LVI who may rely on magnification or experience a partial field of vision. We aim to improve exploration by providing visual access to critical context. To inform this, we conducted a formative study with five LVI. We identified four fundamental contextual elements common across chart types: axes, legend, grid lines, and the overview. We propose two pointer-based interaction methods to provide this context: Dynamic Context, a novel focus+context interaction, and Mini-map, which adapts overview+detail principles for LVI. In a study with N=22 LVI, we compared both methods and evaluated their integration to current tools. Our results show that Dynamic Context had significant positive impact on access, usability, and effort reduction; however, worsened visual load. Mini-map strengthened spatial understanding, but was less preferred for this task. We offer design insights to guide the development of future systems that support LVI with visual context while balancing visual load.