What Does That Mean? Commonly Used Terms Defined-2

Categories: ASD and DD, Child-focused

By Erica Kearney, M.A., LABA, BCBA, and Sarah Helm, M.A., LABA, BCBA

In  previous column, we described five terms commonly used by teachers and therapists who work with children with autism spectrum disorder. These five terms were: ABA (applied behavior analysis), consequence, contingency, reinforcer, and behavioral momentum. In this column, we will define the Premack Principle, explain why discrimination and punishment are not necessarily bad, and define and describe GMI and PECS.
While these terms may be unfamiliar to some and sound a bit like alphabet soup to others, they are key components in effectively treating children on the autism spectrum.
Premack Principle
When employing the Premack Principle, or “Grandma's Law," therapists or teachers ask a child to complete a less preferred activity (putting on sunscreen) before engaging in a more preferred activity (playing outside). In this case, the more preferred activity becomes a reinforcer and improves the chances that the child will then engage in the less preferred activity.
Putting this principle into practice makes it more likely the child will complete the less preferred activity, even if neither activity is something that the child prefers to do. For example, most kids don't love homework or cleaning the yard, but you may be able to get your child to do both by applying Grandma’s Law: "Do your math homework (less preferred), then you can go help Dad clean up the yard (slightly more preferred)."
Through the years, the term “discrimination” has earned a bad reputation. We associate it with the unethical and illegal practice of denying rights, privileges, and respect to certain groups of people. In the field of ABA, however, discrimination is a term used to refer to a person’s ability to distinguish one thing from another. For example, a young child may have a hard time discriminating between a dog and a fox. Because s/he cannot tell the difference between the two animals, s/he refers to both of them as "dog." 
Like “consequence,” the word “punishment’ can often seem a little scary. We think of punishment as being grounded or going to jail. When behavior analysts discuss punishment, however, we are referring to a consequence (what happens after a behavior occurs) that results in an unwanted behavior happening less often. Punishment does not always mean that you are applying a negative consequence. For example, if you ignore your child’s tantrum behavior while they are in the store because you have told them they cannot have a toy they want, then that would be deemed “punishing” because not providing the toy and ignoring the tantrum makes it less likely that they will tantrum for a toy in the future.
GMI is an abbreviation for gross motor imitation. Gross motor refers to large body movements such as touching your head, lifting your arms, waving, or stomping your feet. Gross motor imitation occurs when a student imitates someone else's gross motor movements. To encourage GMI, a teacher might ask a student to move in a certain way, and then demonstrate the movement. This is important because imitation is a skill that typically developing children have which allows them to learn many other important behaviors by imitating their parents. Teaching imitation enables non-typically developing children to learn skills this same way.
Picture Exchange Communication System (PECS)
Picture Exchange Communication System, or PECS, is a form of augmentative communication that helps nonverbal students communicate with others by using picture icons. The icons are usually assembled in a binder or book that a student can carry. When s/he wants to communicate, the student opens the book, finds the appropriate picture icon(s), and hands the icon(s) to the person s/he is attempting to communicate with.
We hope you have found these columns helpful. Other resources that may help you understand the terms used by those who practice applied behavior methodology include:
Behaviorspeak: Glossary of Terms in Applied Behavior Analysis (ABA), by Bobby Newman, Kenneth Reeve, Sharon Reeve, and Carolyn Ryan. Dove and Orca 2003.

A Work in Progress, by Ron Leaf and John McEachin. Autism Partnership 1999.
Behavioral Intervention for Young Children with Autism: A Manual for Parents and Professionals, by Catherine Maurice. Pro-Ed 1996.
Your best resource would be a Board Certified Behavior Analyst (BCBA), a trained clinician with expertise in ABA. If you have any questions, please feel free to contact us at the e-mail addresses listed below.

Erica Kearney, M.A., LABA, BCBA, is Executive Director of the May Center School for Autism and Developmental Disabilities in Chicopee, Mass. She can be contacted at

May Institute is a nonprofit organization that is a national leader in the field of applied behavior analysis, serving individuals with autism spectrum disorder (ASD) and other developmental disabilities, brain injury and neurobehavioral disorders, and other special needs. Founded more than 65 years ago, we provide a wide range of exceptional educational and rehabilitative services across the lifespan. May Institute operates five schools for children and adolescents with ASD and other developmental disabilities, including one in West Springfield, and our newest school in Chicopee, Mass. For more information, call 800.778.7601  or visit