2.4 Making display elements adjustable
Learners may view your content through a range of different devices, screens and browsers. However, there are some common features that you can control that help to make sure the materials display in a form that is accessible to a wide audience. The first is to use as default an accessible combination of settings. So it is good practice to use a font type that has good readability (sans serif fonts are often recommended for printed materials, but online some serif fonts can be suitable if they are not cursive or uneven) and a font size of at least 12 point in text documents (and 20 point on presentation slides). Colour combinations should give good contrast (there is a free colour contrast checker [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] which helps you assess the contrast of colour combinations – you should aim for a minimum ratio of 4.5 to 1 throughout – and for large amounts of text you should aim for a contrast ratio of 7 to 1).
Avoid using flashing or moving elements unless there is a means for users to stop the movement. Also, avoid putting text over background images – this decreases readability dramatically.
The second element of ensuring the accessibility of the display of your materials is to put control into the hands of the learner. If you provide documents created accessibly, the learner will be able to apply their own preference of font, colour and so on. If you are presenting materials to be viewed in a web browser, provide links to guidance on how to use your browser to meet some of your accessibility needs and preferences (such as these resources for Firefox, Internet Explorer, Chrome, and Safari). If you are using another kind of platform to deliver your online teaching (web conferencing, LMS, etc.), try to find out what accessibility features it has, and give guidance to your learners on how to find and use them.
2.3 Making auditory elements accessible