Disabled button or enabled button with potential error message for actions with complex logic behind?

Question

Say I have a button for a complex state machine which can be disabled for a number of reasons. I feel if I run some business logic CanActionBeDoneNow() and simply disable the button if it returns false, the user may be confused as to why he/she can't click it. I see several improvements to this

1. Leave a help-link next to the button which explains why it can't be clicked
2. Let the button be clickable, but show an error message when clicked with an explanation to why the action can't be performed.
3. Actively display the reasons as to why it can't be clicked - either directly under the button or, if applicable, at other visual elements related to the reason* (like in a form where some validation rules are broken).

*) If that was the case 100% of the time, I would go with this solution. But it isn't.

Do you have any input on this? Maybe links to web sites which have some examples on this implemented? Do you agree that the user should be presented with the reason at any point, or should it be left to some passive documentation?

Answer 1

I agree that it would be best to let the user know why the buttons are inactive in-context, rather than relying on passive documentation. If there are complex reasons, having them explained in-context saves a lot of confusion/research for the user, and saves you from having to trust that they read your documentation in detail. You'd be being very kind to them, and very probably cutting down on the amount of support requests.

You could take option 2 a little further and add a "?" icon to your inactive buttons so that, when clicked, a tooltip, or popup explains why the button is inactive. Here it's now visually inactive, but "there's something different about it which indicates further information".

You may choose to show the pop-up on rollover if your application doesn't need to support touch devices.