Tactile Schematics – Design

Close up of hands exploring a tactile schematic of a continuity tester.

Tactile Schematics


Summary

My master’s thesis research is a set standards and best practices for designing tactile schematics for non-visual circuit building.

The library of designed tactile schematics has been published as a resource in NYU ITP’s Physical Computing curriculum, accessed over 1,800 times, and used in two NYU Blind Arduino workshops.

→ Go to Tactile Schematics Website

Role

Researcher, accessibility designer, 2.5D design and prototype production

Academic Advisors

Dr. Amy Hurst
Tom Igoe

Industry Advisors

Dr. Joshua Miele
Chancey Fleet


Demo of hands exploring a schematic before and after the standards & best practices were applied

→ Go to video transcript


Motivation

Problem

Schematics are an integral part to learning electronics. They are drawings of the relationships between components in an electronic device and are used to build circuits. While sighted readers rely on schematic images to understand how electronics work, low vision and blind readers rely on circuit descriptions.

The recording below is called a circuit description. It can be read with a screen reader, either through synthesized speech (the example I’ve provided) or a Refreshable Braille Display. Blind and low vision learners rely on them to understand circuits.

VoiceOver (a screen reader) reading a circuit description

→ Go to transcript

Can you draw that circuit from listening to a description? This is the circuit the screen reader was describing.

Obstacle

As you heard from the screen reader recording above, it’s tough to understand a circuit from a description, especially if you’re a beginner. No tactile graphical representation has yet been able to compete with circuit descriptions.

Electronics beginners can benefit from the spatial information schematics provide and learn the relationships of the components through touch.

Objective

Understand how we can make electronics more accessible to people who are Blind or Low Vision.

A tactile schematic of a continuity tester with alligator clips, a wire cutter, forceps, and the finished project laying around its perimeter.

Educational Tools

  1. Verbal descriptions or interactive simulations for auditory learning
  2. Braille translations for reading/writing learning
  3. Blind Arduino workshops for constructivist learning
  4. Tactile graphics for kinesthetic/tactile learning (the focus of this research)

Educational Resources

  1. The Blind Arduino Project develops and shares techniques for low vision users to build electronics projects
  2. The Andrew Heiskell Braille and Talking Book Library hosts Arduino workshops with the Dimensions program, using tactile methods to learn hardware and software
  3. The Smith Kettlewell Technical File was a publication for Blind or Low Vision electronics enthusiasts and used standardized verbal circuit descriptions instead of diagrams

Personas

Persona for Amanda, textual description link below

→ Long description of persona 1

Persona for Eric, textual description link below

→ Long description of persona 2

Persona for Jo, textual description link below

→ Long description of persona 3


Experience Map

Experience map of a user interacting with tactile schematics.
Timeframe Homework is assigned Homework is started Homework is unfinished Homework is overdue
Activities Opens class site and finds the lab is due Can’t understand the circuit description Has to keep replaying the circuit description Gives up and moves on to the remaining content
Touch Points Phone/laptop Phone/laptop Phone/laptop Phone/laptop
Emotion Line Optimistic Curious Frustrated Hopeless
Pain Points Needs to keep up with the demanding course load Has limited resources for understanding circuits Circuit descriptions are hard for beginners Feels like none of the options are for him
Ideas for Improvement Add other learning style resources to class site Link from class lab to resources presented in another format Schematics are converted to tactile schematics as SVGs Have resources available ahead of the lab due date

User Flow

Close up of hands tapping a schematic on an iPhone.
Eric opens up the Physical Computing site on his phone to see what homework is due. He uses his screen reader to navigate to the lab and listens to the circuit description of how the Arduino should be set up.
Hands tracing the shape of a circuit on a desktop.
He listens to the circuit descriptions, while tracing the outline of its spacial arrangement with his finger on the table. He plays it over and over again to understand.
Hands tapping a smartphone screen and downloading a file.
He continues listening and hears that there is also a tactile schematic available for download. He tabs over to the link to download an SVG of the schematic.
Swell Touch Paper being fed through a Swell Form Machine.
He prints the schematic on Swell Touch Paper and runs through a Swell Form Machine. The black Braille and outlines of the schematic puff up.

Hands exploring a tactile schematic.
He feels the raised surfaces and builds a mental model. He gets his Arduino out and hooks it up, periodically reaching over and double checking with the tactile schematic to make sure he has the right pin connections.

Finger pressing a button on a breadboard with a piezo.
The piezo buzzes when he presses the button which means the circuit works.

Prototyping

Design Iterations

Original analog in circuit as displayed on the NYU website, not optimized for tactile perception
Original file: Analog In as downloaded from the Physical Computing site. It is tiny, there’s text, and some of the lines are gray so they won’t puff up in the Swell Form Machine
1st iteration of analog in tactile schematic with the key on the same page and poorly designed schematic symbols
Version 1: First iteration of Analog In. The entire layout is much too cluttered, the gray text color contrast ratio is 3.03:1, which is not accessible, the Braille plus sign is incorrect, and the size of the components aren’t yet optimized using iterative design
11th iteration of Analog In tactile schematic with braille, high contrast text labeling, and optimized symbol sizing
Version 11: Final iteration of Analog In, in which the layout has been rotated to avoid clutter, the text color has been changed to a 10:01 color contrast ratio, but still won’t puff up on the Swell Form, the Braille plus sign has been corrected, the symbols have been optimized from user feedback, and the slash mark adheres to upper right-hand corner conventions

Production Workflow

Manual feed tray in a color laser printer ejected and loaded with Swell Touch Paper.
Paper is loaded so that it prints on the sticky, coated side of the paper
Close up of Swell Form Machine dial set to Medium.
Test printing helps determine the best heat setting for the paper and heater you’re using
Swell Touch Paper being fed through a Swell Form Machine.
The paper is inserted, following the direction of the arrow, the carbon in the black ink reacting to the heat and puffing up

Research Method

Recruiting

We recruited 5 Blind and Low Vision participants through our professional network. They represented a range in learning style, finger variables (sensitivity and size), electronics experience, Braille literacy, and visual acuity.

Procedure

We conducted our research through NYU’s Institutional Review Board. We presented participants with tactile versions of The Big 6—or the six schematics crucial to understanding Physical Computing—given informed consent, a series of tasks, asked to identify specific electronics components, and explain the schematic in their own words.

Hands touching common component symbols and reading the Braille label to the right of it.

Interview Questions

Introduction

  1. Tell me about your experience with electronics?
  2. Tell me about your experience with tactile graphics?

Circuit Description Usability

  1. Go to this site and have a look at the page.
  2. I’m going to send a circuit description to your email for you to listen with your screen reader.
  3. What is title of the schematic?
  4. Will you find the resistor?
  5. Can you tell what kind of resistor is depicted?
  6. Will you tell me many LED’s are shown here?
  7. Can you see if you can tell where is ground located?
  8. How would you explain the schematic back to me in your own words?
Hands exploring the schematic of an LED, Resistor, Regulator in Series during a usability test.

Tactile Schematics Usability

  1. What is title of the schematic?
  2. Will you find the resistor?
  3. Can you tell what kind of resistor is depicted?
  4. Will you tell me many LED’s are shown here?
  5. Can you see if you can tell where is ground located?
  6. How would you explain the schematic back to me in your own words?

Follow-up Questions

  1. Which is more clear to you? Which do you prefer, the circuit descriptions or the tactile schematics?
  2. How do you feel about the material you’re seeing here?
  3. What are your thoughts about the tactile graphics?
  4. Do you have any suggestions for the design of these graphics?
  5. Do you see any other uses in  your life for tactile graphics?

Conclusion

There is no universal solution

We still need to do more research to determine if these are as effective as circuit descriptions and evaluate combining the two modalities.

Tactile graphic evaluation changes with each use case

How do we evaluate tactile graphic readability given the variability of usage? Because their effectiveness isn’t universal, I would always have to tailor them to the audience I’m designing them for. For example, one user might prefer Braille, one might prefer high contrast ratio text.

We need more non-visual circuit building workflows

Can tactile schematics go beyond understanding how a circuit works to actually hooking one up? This is the beginning stage of much larger scope of work to see if we can develop a non-visual workflow for building circuits.


Tactile Schematics for ITP’s Physical Computing Course

Overhead view of a tactile schematic of a piezo, resistor in series. There is a braille label at the top, a page-orientation slash in the upper right-hand corner, and a schematic of an Arduino hooked up to a resistor, piezo buzzer, and ground.
Printed tactile schematic from the Physical Computing library
Page from the style guide that shows how to improve line consistency for tactile discernibility
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