17
votes
7answers
1k views

Greyed-Out vs Invisible

What is a good criterion or rule-of-thumb for determining when a control should be greyed-out and when should it be completely invisible?
22
votes
13answers
1k views

Is it better to prevent a forbidden action or display an error/explanation message?

There are multiple examples, so I'll pick a specific one to focus the question. Let's say a user can have specific characteristics (or permissions): Admin, Virtual, External, Financial, etc. To ...