AbstractChallenging behaviors (CB) in the form of self-injurious behaviors, aggression, property destruction, tan-trums, pica, and other disruptive activities are common among persons with intellectual disabilities. Lack of social and com-munication skills, temperament issues, and other symptoms that characterize these persons contribute to the high rates of CB. In recent years, applied behavior analysis (ABA) has proven to be a particularly effective treatment for these issues. Functional assessment is a foundational strategy for such intervention. The methods most commonly used to achieve this goal include interviews and observations, experimental functional analysis, in vivo assessment, and standardized tests. The purpose of this group of techniques is to establish the variables that maintain the behavior, and treatment then flows
from these data. This paper reviews the current state of the art in the area of functional assessment. KeywordsAggression. Applied behavior analysis. Challenging behavior. Self-injurious behavior. Intellectual disability. Developmental disorders. Functional assessment. Functional analysis.Intervention