Fluency training focuses on increasing the speed of accurate responding (Martens & Witt, 2004). This research was conducted with an elementary aged boy diagnosed with autism who responded accurately, but slowly to calendar and time related questions. Set in a public school, the student's personal aide was trained to make rewards contingent on quick, or fluent, responding. Using a changing criterion design the number of consecutive fluent responses required to earn a reward was systematically increased. At the beginning of the study the student was engaged 10 consecutive discrete trials (Lovaas, 1987) during a session and responding was slow. By the end of the study the student was engaged for 12 consecutive trials and was responding to each question fluently, within 3-seconds. The design of the study allows for causal statements to be made about the effects of contingent rewards on the student's fluent responding. (Contains 2 figures.)