Teaching Purchasing Skills Through the Application of Constant Time Delay to Students with Moderate Mental Retardation during Community-Based Instruction

A constant time delay procedure was used to teach two students with moderate mental retardation how to purchase food at local fast food restaurants and snacks at a local convenience store. Students were taught to purchase the items using paper money and were required to determine the amount due by locating the next dollar up amount on a number line. A 5-second time delay was used in teaching the subjects these purchasing skills. Training was evaluated with a multiple probe design across settings. Results indicated subjects did not reach criterion in the fast food setting. In the convenience store setting subjects did not reach the criterion level; however, subjects made substantial improvements in their purchasing skills