Universal Design for Learning (UDL): User ability variations

Conditions to consider:

1. Blindness – Make sure there is an audio option either embedded, or the material can be read by a screen reader.  Provide audio descriptions, or screen readable text.
2. Color blindness – do not use color only for navigation or other signifiers.  Make sure there is high contrast between text and background.
3. Low vision – Font should be 14px or larger. Make sure there is high contrast between text and background. Make sure there is an audio option either embedded, or the material can be read by a screen reader. 
4. Deaf or hard of hearing – Provide text, transcript, or closed captioning for audio content.
5. Poor motor control – Separate clickable links with enough distance to make sure selection is more accurate.  Don’t assume everyone can use a mouse.
6. Can’t use mouse – Make sure web pages can be navigated by tab key or arrow keys.
7. Can’t use keyboard arrows – Make sure pages can be navigated with just tab key.
8. Dyslexia – Use san-serif font (no curls on the letters) for online text. Keep it simple and straight forward.
9. Short attention span – Keep it simple.  Less text.  Easy to follow.
10. Low threshold for complexity – Have person who is not familiar with page try it and give feedback.  You know too much and probably expect users to be more computer or subject literate than they are.
11. Lack of experience – Spell it out, don’t assume your users know what you know.