Luke Wroblewski on Inline Validation

http://www.alistapart.com/articles/inline-validation-in-web-forms/

When it comes to web form design and usability testing Luke Wroblewski is the guru. This is his latest study, showing how to best do inline validation (and showing that it’s well worth the effort).

When done right it showed:

• 22% increase in success rates
• 22% decrease in errors made
• 31% increase in satisfaction rating
• 42% decrease in completion times
• 47% decrease in the number of eye fixations