Here is a particularly poignant extract from the article:
The survey asked respondents to select their most, second
most, and third most problematic items from a list. In giving each selected item a weighting, the following chart shows the amount of difficulty and frustration users encounter with each item. Problematic items identified are, in order (most difficult/confusing first):
- CAPTCHA - images presenting text used to verify that you are a human user
- The presence of inaccessible Flash content
- Links or buttons that do not make sense
- Images with missing or improper descriptions (alt text)
- Complex or difficult forms
- Lack of keyboard accessibility
- Screens or parts of screens that change unexpectedly
- Missing or improper headings
- Too many links or navigation items
- Complex data tables
- Lack of “skip to main content” or “skip navigation” links
- Inaccessible or missing search functionality
