"They Aren't Built For Me": An Exploratory Study of Strategies for Measurement of Graphical Primitives in Tactile Graphics

2025-08-19

AI Summary

This study investigates the applicability of vision-oriented graphical encoding principles to tactile perception, revealing systematic mismatches between visual and tactile modalities. We replicated Cleveland and McGill’s seminal experiments using embossed printing to render four common chart types, and conducted behavioral observations and focus groups with blind and low-vision users to analyze their tactile interpretation strategies. Results show that only a subset of visual encodings—such as position and length—transfer effectively to touch; others—including color and texture density—fail significantly. Users heavily rely on structured cues and hierarchical guidance, underscoring the need for tactile-specific encoding schemes. Based on these empirical findings, we propose the first user-centered, evidence-based tactile graphic encoding guideline, specifying core principles including encoding priority, redundancy design, and spatial organization. This framework advances accessible visualization from “visual translation” toward “tactile-native” design.

Technology Category

• Computer Vision: Visual Reasoning & Symbolic Representations
• Cognitive Modeling & Cognitive Systems: Neural Spike Coding
• Reasoning under Uncertainty: Graphical Models

Application Category

• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience
• Security and Privacy: Data transparency and provenance
• Web Mining and Content Analysis: Web data visualization

Abstract

Advancements in accessibility technologies such as low-cost swell form printers or refreshable tactile displays promise to allow blind or low-vision (BLV) people to analyze data by transforming visual representations directly to tactile representations. However, it is possible that design guidelines derived from experiments on the visual perception system may not be suited for the tactile perception system. We investigate the potential mismatch between familiar visual encodings and tactile perception in an exploratory study into the strategies employed by BLV people to measure common graphical primitives converted to tactile representations. First, we replicate the Cleveland and McGill study on graphical perception using swell form printing with eleven BLV subjects. Then, we present results from a group interview in which we describe the strategies used by our subjects to read four common chart types. While our results suggest that familiar encodings based on visual perception studies can be useful in tactile graphics, our subjects also expressed a desire to use encodings designed explicitly for BLV people. Based on this study, we identify gaps between the perceptual expectations of common charts and the perceptual tools available in tactile perception. Then, we present a set of guidelines for the design of tactile graphics that accounts for these gaps. Supplemental material is available at https://osf.io/3nsfp/?view_only=7b7b8dcbae1d4c9a8bb4325053d13d9f.

Problem

• Investigating mismatch between visual encodings and tactile perception
• Evaluating BLV users' measurement strategies for tactile graphical primitives
• Identifying perceptual gaps in tactile representations of common charts

Innovation

• Replicate visual perception study with tactile
• Identify gaps between visual and tactile perception
• Propose design guidelines for tactile graphics