One control that is applicable for almost any system is "enter data close to the originating source". A customer entering a purchase into an online sales system (such as at Amazon.com) is an excellent example of this control.

In about 250 words (i.e. one page double spaced), describe the details of why a process with this control would produce fewer errors than a process where the sales clerk manually writes down the customer's order. Be sure to address the concepts of input validity, input completeness, and input accuracy in your answer.