What is the Modified Overt Aggression Scale (MOAS)?

The MOAS is a behavioral rating scale designed to assess four categories of aggressive behavior in institutional settings such as hospitals, residential facilities, or correctional institutions.

Who developed it and when?

Developed by Kay et al. in 1988 as a modification of the original Overt Aggression Scale (OAS) by Yudofsky et al. (1986).

What type of assessment is it?

Behavioral rating scale with frequency-based scoring for aggressive behaviors.

What does it assess?

• Verbal Aggression: Threatening or insulting language
• Aggression Against Property: Damage to objects or environment
• Auto-Aggression: Self-injurious behavior
• Physical Aggression: Violence against other people

How many items and what format?

16 items across 4 domains, rated on frequency scales from 0 (never) to 4 (very frequently).

How is it scored?

Each domain receives weighted scores, with physical aggression having the highest weight. Total scores range from 0-40.