The Web Content Accessibility Guidelines (WCAG) is an initiative run by World Wide Web Consortium (W3C) to ensure web content is universally accessible. For more details on WCAG please see this article.

WCAG is organised around four main principles, often referred to by the acronym POUR: Perceivable, Operable, Understandable, and Robust. These principles allow web designers and web content providers to consider/design websites that are accessible to users regardless of their abilities or the assistive technologies they use.

This article delves deeper into the first of the POUR Principles: ‘Perceivable’ and how it applies to online surveys:

The original accessibility guidelines focused on people with visual impairment.  Websites were simpler and so they mostly provided the opportunity to consume written information.  Perceivable says that text content must be visually clear; non-text content should include alternative textual descriptions.

• Sufficient text size and colour contrast
• Text alternatives for important images
• Captions for audio, and audio description for video

Survey components must be presentable to users in ways they can perceive. For those who struggle to see, this means providing captions for images that can be read out by screen readers. 

For those who need large fonts (to zoom in) the survey page must adjust and yet still perform its purpose. 

For those who struggle to perceive changes in colour or tone, text colour and background colour should be easily distinguishable.  Colour should never be used alone to denote something (e.g. red for error without either the word error or some captioned graphic stating error). When playing a video, the video content should have audio descriptions. When showing an image it should accompanied by a description (example below).

Image showing how an example of an icon and its alternative text description

If an image conveys no important information necessary for the user to understand the survey content, it can be considered ‘decorative’ because its only function is to enhance the appearance of the survey page. Decorative images do not need to be described.

And remember that for multilingual surveys, you will need to translate the alternative text for any images or the audio descriptions for videos.

In summary: 

Survey content must be legible, regardless of how it is accessed.