Aza Raskin has done some excellent work regarding Modal dialogs.  Almost every single application in the world has modal dialogs.  They are nearly ubiquitous.  One of Aza’s points is that a modal with just an [OK] button is nearly useless.  I usually try to think about modals as if they were a verbal conversation between the user and the application.  If it sounds like an awful conversation between system and user when you play it out, it probably is a bad interaction.

In the app I design, there used to be a way to delete many of the important objects in the database.  This was an important feature, but also a dangerous one for obvious reasons.  Saying “This will delete these leads, are you sure?” was no working.  People ignore these sorts of messages.  I needed to get them to think more clearly about the problem.  This is what I came up with:

Several “features” of this modal.

1. Imagery.  On the one hand, it wakes people up.  “Ooh, this looks serious!”  On the other hand it is partially whimsical.  “Ooh, that’s cute!”  It simultaneously pokes the user in the brain in two different ways.
2. Language.  I say, “Delete, Destroy, No Going Back, Can Not Undo, Erase”. I tried to use every conceivable language that will get the user to think, “Hmm, will this really delete these leads?”
3. Makes them think to complete the task.  The bottom right button is disabled until they put in the correct number of leads that will be destroyed.  Additionally, they need to check the box.  You can’t just click YES.  You need to think to come up with the correct number.

This modal was an unqualified success.  The problem (“I accidentally deleted my leads”) has never happened since the modal was put in place.  Additionally, several comments on it’s effectiveness have been received.  I love this modal because it accomplishes its goals without being mean to the customer.

Use techniques like this to think out of the box and accomplish your goals using psychology.  People may be irrational, but they all share a common human psychology.  Be whimsical & friendly but don’t let them make terrible mistakes.