A criterion often used to determine whether a child has a learning disability. Some districts have developed their own.
Some scholarly texts offer alternative formulae.
ADA - Americans with Disabilities Act of 1990. This law follows the principles established under Section 504. It provides for the protection from discrimination of persons with disabilities and allows claims for compensatory and punitive damages. It is usually measured by scales that identify how well a person manages within his or her own environment. ADHD - Attention Deficit Hyperactive Disorder.