Kids in Mrs. May's kindergarten classroom are engaging in some frequent episodes of off-task behavior during center time, such as leaving their assigned center. Mrs. May places a chart on the SmartBoard that is divided into 5 blocks, each block representing 4 minutes of time, for a total of 20 minutes (the time that centers are open). She tells the students that if they leave their designated center fewer than 2 times (without first asking permission to do so) in a 4-minute interval, she will place a shape in one of the blocks on the SmartBoard. Then, at the end of center time, she will count up the number of shapes the children have earned and will award them 1 minute extra of recess for every shape earned - for up to 5 extra minutes of recess! What DR procedure is this