This xkcd comic strip nails one of the most frequent problems with modern web interfaces. Â Web forms will ask you confirm and re-confirm anything and everything, but the actual important information that is easy to make a mistake with. Â The rule of thumb here is, of course, only ask to confirm the password fields, because the data in them is not visible, so it does make sense to check that the user actually typed in what he thinks he typed in. Â Asking to enter email address once again is stupid, because, email address is usually displayed in a visible field, because email address is a frequently used string, which most people type automatically, and because the user won’t bother with re-typing but will just copy-and-paste from a previous field.
