Evaluating accessibility of a 3D CAD application

Summary

To comply with a non-disclosure agreement, I have omitted all the confidential information from this project. The details mentioned in this post are my own and do not reflect the views of any company.

 

  • The accessibility of eDrawings Pro, a professional 2D and 3D CAD app for Apple and Android devices was evaluated.
  • I was part of a two member team which created an in-house accessibility audit process that helps to evaluate the progress in the accessibility of a native application over time. 
  • Identified areas in the app where users with limited abilities may face problems. Furthermore, we provided recommendations to solve them based on best practices from WCAG and other guidelines.

Problem statement

How can users with limited abilities access information in a 3D CAD file and collaborate through a native mobile application?

Approach

Creating an accessibility audit

  • Due to the lack of native applications accessibility guidelines, we created an in-house accessibility audit checklist.
  • Based this checklist on the structure of the Voluntary Product Accessibility Template (VPAT) and guidelines from WCAG 2.0, 2.1, UAAG, Section 508.
  • Recommendations were inspired by Google’s Material Design and Apple’s Human interface accessibility guidelines.

Devices and accessibility features used

 

  • eDrawings pro is available on Apple and Android. We conducted the accessibility study using the following devices:

      1. iPad Pro (12.9’)
      2. iPhone 6 Plus
      3. HTC Nexus 9
      4. Samsung Galaxy S9

  • Following accessibility features were used for evaluation across android and iOS (mobiles and tablets).

      • Accessibility Scanner (Android)
      • TalkBack (Android)
      • VoiceOver (iOS)
      • Zoom (iOS)
      • Smart Contrast (iOS)
Devices used for the accessibility study

Task overview

  1. Open .easm file in the eDrawing app
  2. View the model by using the rotate, pan, and zoom features
  3. Use the section feature in the YZ plane and hide the caps of the sectioned area
  4. Measure the distance between two edges
  5. Use the navigation tree to show/hide parts and use solid/transparent mode
  6. View other configurations of the model
  7. Access help to figure out how to use the markup feature
  8. Insert a markup in any location

Evaluation process

  • Based on Practical Usability Ratings by Expert (PURE) methodology, we created a task list dividing them by steps and substeps.
  • Each substep is evaluated and scored based on these rubrics
      1. Abides by the accessibility principles, and the user is able to complete the task
      2. Doesn’t abide by the accessibility principles, but the user is still able to complete the task 
      3. Doesn’t abide by the accessibility principles, and the user is not able to complete the task
  • Cumulative score of substeps = PURE score of the step
  • Highest severity among all substeps = Severity of the step
  • This method ensures that the same criteria for evaluation are considered after fixing issues in the app.

A few high-level findings

Picture illustrating the low contrast ratio and small button in a phone screen
  • The tap targets on the Android app (Mobile, Tablet) and iOS app (Mobile) were below the recommended accessible size.
  • The contrast ratio of some drop downs in the Android mobile app does not meet the minimum accessibility recommendations.
  • Functions like rotate, pan, zoom do not work with the accessibility features in iOS. 
  • The screen reader doesn’t prompt how to rotate, pan, and zoom when the user clicks the graphics array for the first time in a session.
Picture showing the cut function in landscape
  • Some icons were below the recommended accessible size of 44px
  • The screen reader doesn’t prompt the status of a feature consistently.
Picture showing the measuring functionality on a tablet computer
  • Doesn’t detect multi-finger touch to move the measuring cursor.Thus the user cannot measure the distance. 
  • Instructions for such interactions are not given out by the screen reader.

Deliverables and results

  • Delivered the accessibility audit template that includes checklists and recommendations.
  • Majority of the accessibility issues can be solved by adding alt texts and labels.
  • Recommended to try leveraging multi-finger gestures to enable model interactions.
  • Recommended to increase button size, especially for mobile devices.