The article by Edward G. Carr and V. Mark Durand explores methods to reduce behavior problems in children with developmental disabilities through functional communication training. The authors conducted two experiments to identify and address the underlying causes of misbehavior and to develop effective replacement behaviors. **Experiment 1** aimed to develop an assessment method to identify situations where behavior problems, such as aggression, tantrums, and self-injury, are most likely to occur. The results showed that low levels of adult attention and high task difficulty were discriminative for misbehavior. This information was used in **Experiment 2** to select appropriate replacement behaviors. In **Experiment 2**, the children were taught to verbally request attention or assistance from adults. This treatment, involving differential reinforcement of functional communication, successfully reduced behavior problems across four developmentally disabled children. The findings support the hypothesis that some child behavior problems may be viewed as nonverbal means of communication, and strengthening verbal communication can weaken these problems. The authors conclude that behavior problems can be reduced by teaching children communicative phrases that alter the stimulus conditions controlling the problems. The selected phrase must be functionally related to the controlling stimuli, and the specific form of the verbal response is less important than the consequence that follows. Communication training provides an active role for children, teaching them that communicative behavior can produce consistent and useful social effects.The article by Edward G. Carr and V. Mark Durand explores methods to reduce behavior problems in children with developmental disabilities through functional communication training. The authors conducted two experiments to identify and address the underlying causes of misbehavior and to develop effective replacement behaviors. **Experiment 1** aimed to develop an assessment method to identify situations where behavior problems, such as aggression, tantrums, and self-injury, are most likely to occur. The results showed that low levels of adult attention and high task difficulty were discriminative for misbehavior. This information was used in **Experiment 2** to select appropriate replacement behaviors. In **Experiment 2**, the children were taught to verbally request attention or assistance from adults. This treatment, involving differential reinforcement of functional communication, successfully reduced behavior problems across four developmentally disabled children. The findings support the hypothesis that some child behavior problems may be viewed as nonverbal means of communication, and strengthening verbal communication can weaken these problems. The authors conclude that behavior problems can be reduced by teaching children communicative phrases that alter the stimulus conditions controlling the problems. The selected phrase must be functionally related to the controlling stimuli, and the specific form of the verbal response is less important than the consequence that follows. Communication training provides an active role for children, teaching them that communicative behavior can produce consistent and useful social effects.