Table 3.

Operational Definitions of Challenging Behaviors

Variable	Operational Definition
Repetitive Behavior	Any movements without purpose that are repeated in a similar manner and in close succession (e.g., body rocking, swaying, hand flapping, jumping, bouncing, head nods, and spinning/twirling objects) OR any vocal repetition of words or phrases that occur in close succession.
Negative Affect	Any expression of negative emotions (e.g., frowning, crying, whining, or screaming).
Aggression	Any inappropriate physical contact (aimed at a person or object) with force that may leave a mark or result in physical or tangible harm/injury (e.g., hitting, kicking, grabbing, pinching, head butting, biting, or throwing).
Self-injurious Behavior	Any actions that cause or have the potential to cause physical harm or injury to self (e.g., self-hitting, head banging, self-pinching, hair pulling, or biting).