Designing Interactions for 3D Printed Models with Blind People
Lei Shi, Yuhang Zhao, Shiri Azenkot · 2017 · Proceedings of the 19th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '17) · doi:10.1145/3132525.3132549
Summary
This paper investigates how blind people explore 3D printed models and what interaction techniques they prefer for interactive 3D printed models (I3Ms) — physical models augmented with sensors that provide audio descriptions when touched. While 3D printing has become increasingly affordable and accessible, enabling teachers, students, and makers to create tactile models of everything from biological cells to architectural structures, prior research on I3Ms focused primarily on the technical sensing aspects rather than understanding how blind users actually interact with the models. The researchers conducted a two-section study with 12 legally blind participants (ages 23-60) using three 3D printed models: a biological cell, a globe, and a map of buildings. In the Exploration section, participants performed tasks such as identifying models and describing specific elements while thinking aloud. In the Elicitation section, participants were asked to design input techniques for six interactive functions (e.g., getting general model information, selecting elements, recording notes) using a Wizard-of-Oz approach where researchers simulated audio feedback. The study used video analysis with note cards to code exploration behaviors, and calculated max-consensus and consensus-distinct ratios for elicited interactions.
Key findings
The study identified five distinct exploration activities blind participants performed: sensing (texture and shape), measuring (using hands to gauge element sizes via proprioception), comparing (touching two elements to confirm similarity), counting (tallying repeated shapes), and communicating (indicating, explaining, and inquiring with researchers). Participants used four hand postures: Grabbing (holding model in air with one hand), Stabilizing (fixing model on table with one hand), Diverging (two hands on separate elements), and Converging (both hands on one element). Eight gestures were catalogued across single-finger (pointing, striking, index scanning, thumb scanning) and multi-finger categories (pinching, hovering, following, rubbing). In the elicitation section, participants proposed 82 interactions across three modalities: gestures (68.3%), speech input (15.9%), and buttons (15.9%). Gestures had the highest variety with 40 distinct techniques. Key design implications emerged: models should offer multiple detail levels to avoid overwhelming users, audio content should be controllable with modes and switches to prevent information overload, auxiliary components (like handles) should support rather than hinder exploration, and gestures should be both learnable and distinguishable from natural exploration movements.
Relevance
This research provides foundational design knowledge for an emerging accessibility tool. As consumer 3D printers become ubiquitous in schools, libraries, and homes, the potential for creating tactile learning materials for blind people grows enormously — from STEM education models to architectural maps to data visualizations. The study's detailed taxonomy of exploration behaviors (activities, postures, and gestures) gives designers a practical framework for building I3Ms that align with how blind users naturally interact with physical objects. Particularly valuable is the finding that models need multiple versions at different complexity levels, since participants with varied tactile perception abilities found some models overwhelming. The caution about distinguishing intentional gestures from natural exploration movements is critical for any sensor-based tactile system. For practitioners working on tactile accessibility in education or public spaces, this paper offers concrete guidance on designing interactive physical objects that provide audio-augmented information without disrupting the tactile exploration process.
Tags: 3D printing · blindness · tactile perception · interaction design · participatory design · haptic technology · elicitation study · assistive technology