Factor structure of the Motivation Assessment Scale

Area of Science:

• Developmental Psychology
• Behavioral Analysis
• Clinical Psychology

Background:

• Problem behaviors in individuals with developmental disabilities are often controlled by specific functions.
• The Motivation Assessment Scale (MAS) was developed to identify these functions.
• Previous validation relied on face validity and limited correlational studies.

Purpose of the Study:

• To validate the factor structure of the MAS in different settings.
• To determine the clinical utility of the MAS in identifying controlling functions of self-injurious behavior.
• To assess the impact of behavior frequency on the MAS factor structure.

Main Methods:

• Factor analysis with varimax rotation was applied to MAS ratings from two samples (N=60 residents, N=96 students).
• Self-injury was the target behavior, with varying frequencies between institutional and school samples.
• Ratings were collected from staff in residential facilities and teachers in schools.

Main Results:

• A meaningful four-factor structure (sensory, escape, attention, tangible) emerged for the institutional sample.
• The factor structure was not clearly defined for the school sample with lower frequency behaviors.
• The MAS demonstrated a robust factor structure for high-frequency self-injury.

Conclusions:

• The MAS possesses a robust factor structure and potential clinical utility for predicting problem behavior functions.
• The scale's effectiveness is contingent on the target behavior occurring at a minimum rate of 15 responses per hour.
• Further research may refine the MAS application across diverse behavioral frequencies and settings.