The purpose of the proposed project is to develop a precise methodology for identifying the effects of establishing operations (Eos) on severely destructive behavior exhibited by children with developmental disabilities. One of the most important Eos related to destructive behavior for children is deprivation/satiation of adult attention. The specific aim is to analyze the effects of Eos on both destructive and socially appropriate behavior during analogue conditions in which the child is ignored for brief periods but attention continues to be contingent on destructive behavior. Six children between the ages of 5 and 13 who are diagnosed with developmental disabilities will participate. Assessment for each subject will take place in his or her classroom and will be conducted in three phases. In Phase I, a functional analysis will be conducted to identify the existing reinforcers for destructive behavior. In Phase II, the effects of the absence/presence of attention as an establishing operation for destructive behavior will be assessed. A comparison will be conducted of two antecedent conditions: 10- min no attention and 10-min attention on destructive behavior in subsequent 10-min ignore conditions. In Phase III, the effects of the duration of attention of destructive behavior will be examined. A comparison will be conducted of the effects of 10- min attention and 5-min attention on destructive behavior in subsequent 10-min ignore conditions. During all ignore conditions, each occurrence of destructive behavior will result in 10-s of attention. Single-subject experimental designs will be used in each phase of the assessment. For each subject, assessment will take approximately 17 weeks. The results of the proposed project are expected to demonstrate an effective methodology for precisely identifying the effects of EOs on severely destructive behavior. This methodology will be used to develop treatment models based on EOs to be reviewed for subsequent funding.