Original text - English - However, the help they provide is limited by...

However, the help they provide is limited by several flaws:
The result is that many GUIs are full of design errors. Some errors are semantic
and can be detected only by people who understand the application’s target
users and tasks. However, many GUI design errors would be easily detected by
most UI professionals, even those unfamiliar with the users and tasks. Such
errors are GUI control bloopers. They fall into two categories: