This article discusses the use of functional communication training (FCT) to reduce behavior problems in children with developmental disabilities. The authors conducted two experiments to address the issue of choosing appropriate replacement behaviors for misbehavior. In Experiment 1, they developed an assessment method to identify situations where behavior problems, such as aggression, tantrums, and self-injury, were most likely to occur. They found that low levels of adult attention and high levels of task difficulty were discriminative for misbehavior. In Experiment 2, they used this assessment data to select replacement behaviors, teaching children to solicit attention or assistance from adults. This treatment, which involved differential reinforcement of functional communication, produced replicable suppression of behavior problems across four developmentally disabled children. The results supported the hypothesis that some child behavior problems may be viewed as a nonverbal means of communication. According to this hypothesis, behavior problems and verbal communicative acts, though differing in form, may be equivalent in function. Therefore, strengthening the latter should weaken the former. The article also discusses the importance of identifying the social function of behavior problems, such as escape or attention-seeking, and selecting appropriate replacement behaviors. It highlights the effectiveness of teaching children to solicit attention or assistance verbally, which can reduce behavior problems. The study found that children who were taught to use relevant communicative phrases, such as "I don't understand" or "Am I doing good work?", showed a significant reduction in disruptive behavior. In contrast, children taught irrelevant phrases did not show a decrease in behavior problems. The results suggest that the effectiveness of communication training depends on the functional relationship between the communicative phrase and the specific nature of the child's behavior problems. The article concludes that communication training is an effective strategy for reducing behavior problems in children with developmental disabilities, as it provides them with a functional means of communication that can produce consistent and useful social effects.This article discusses the use of functional communication training (FCT) to reduce behavior problems in children with developmental disabilities. The authors conducted two experiments to address the issue of choosing appropriate replacement behaviors for misbehavior. In Experiment 1, they developed an assessment method to identify situations where behavior problems, such as aggression, tantrums, and self-injury, were most likely to occur. They found that low levels of adult attention and high levels of task difficulty were discriminative for misbehavior. In Experiment 2, they used this assessment data to select replacement behaviors, teaching children to solicit attention or assistance from adults. This treatment, which involved differential reinforcement of functional communication, produced replicable suppression of behavior problems across four developmentally disabled children. The results supported the hypothesis that some child behavior problems may be viewed as a nonverbal means of communication. According to this hypothesis, behavior problems and verbal communicative acts, though differing in form, may be equivalent in function. Therefore, strengthening the latter should weaken the former. The article also discusses the importance of identifying the social function of behavior problems, such as escape or attention-seeking, and selecting appropriate replacement behaviors. It highlights the effectiveness of teaching children to solicit attention or assistance verbally, which can reduce behavior problems. The study found that children who were taught to use relevant communicative phrases, such as "I don't understand" or "Am I doing good work?", showed a significant reduction in disruptive behavior. In contrast, children taught irrelevant phrases did not show a decrease in behavior problems. The results suggest that the effectiveness of communication training depends on the functional relationship between the communicative phrase and the specific nature of the child's behavior problems. The article concludes that communication training is an effective strategy for reducing behavior problems in children with developmental disabilities, as it provides them with a functional means of communication that can produce consistent and useful social effects.