If the members of a functional response class occur in a predictable order, a response-class hierarchy is said to exist. Although this topic has received some attention in the applied literature, it remains relatively understudied. The purpose of the current investigation was to develop an analogue model of a response-class hierarchy. Children with and without developmental disabilities were first taught three responses in an attempt to develop a functional response class ordered along the dimension of response effort (Experiment 1). Following response-class development, an extinction analysis was used to determine whether the responses were hierarchically related (Experiment 2). Results of Experiment 1 indicated that a functional response class was developed, and that there was a relation between response rate and effort for the established response class. Results of Experiment 2 indicated that a response-class hierarchy existed within the previously developed response classes for 3 of 4 participants. (Contains 6 figures.)