Error prevention

For all systems, we must, as computer professionals, protect users from their own errors, intercept all detectable errors, and give informative warnings when we believe the user might have made an error.  The “she made and error and must take responsibility” defense is too simple.  We need systems that work in collaboration with the user such that the overall error rate drops to a minimum.  Yes, we need responsible users, but a good system can handle most slips and typos they make.