What Is a Preference Assessment? The Key to Motivation in ABA
Imagine being asked to work a difficult job for a currency you didn’t value. If you don’t like coffee, a free latte isn't going to motivate you to finish a complex report. If you don’t care for sports, front-row tickets won't inspire you to put in extra hours.
In Applied Behavior Analysis (ABA), we understand that "one person’s trash is another person’s treasure." To help a child learn difficult new skills—like speaking, sharing, or following routines—we must first identify what truly motivates them. This is where the Preference Assessment comes in. It is a systematic tool used to discover a child’s "currency."
Why We Don't Just Guess
It is tempting to assume we know what a child likes. "He’s a boy, so he must like cars," or "She’s three, so she’ll love stickers." However, many autistic individuals have highly specific and unique interests. A child might find the spinning wheels of a car fascinating but have zero interest in "racing" them.
A preference assessment removes the guesswork. It is a data-driven way to rank items from "highly preferred" to "lowly preferred." This ensures that when we ask a child to do something challenging, the reward on the other side is actually worth the effort.
Common Types of Preference Assessments
There are several ways a therapist might conduct an assessment, depending on the child’s age and ability level:
1. Free Operant Observation
This is the most "natural" method. The therapist places the child in a room full of different toys and simply watches. They record how much time the child spends with each item. If the child spends 10 minutes with a light-up wand and 10 seconds with a puzzle, we know the wand is a high-priority motivator.
2. Paired Stimulus (The "Forced Choice")
The therapist holds up two items (e.g., a bubble wand and a dinosaur) and asks the child to "Pick one." This is repeated until every item has been compared against every other item. This creates a clear "hierarchy" of what the child wants most.
3. Multiple Stimulus Without Replacement (MSWO)
The therapist puts a group of items (usually 5–7) in a line. The child picks one. Once they play with it, that item is removed from the lineup, and the child chooses from the remaining items. This is a fast way to see a child's first, second, and third choices.
Preference vs. Reinforcer: The Big Distinction
It is important to note that just because a child likes something doesn't mean it will work as a reinforcer.
A Preference is something a child enjoys.
A Reinforcer is something that, when given after a behavior, causes that behavior to increase in the future.
A therapist uses a preference assessment to find "candidates" for reinforcement. If a child loves bubbles (preference) and starts using more words to ask for them (reinforcement), we have found a winning tool for their learning.
The "Ever-Changing" Hierarchy
Preferences aren't permanent. Think about your favorite song; if you heard it 50 times in a row, you’d eventually want to turn it off. This is called satiation.
ABA therapists conduct preference assessments frequently—sometimes at the start of every session—to account for these changes. A child might love goldfish crackers at 10:00 AM but be bored of them by 11:00 AM. By constantly checking in, we ensure the "motivation engine" of the therapy session never runs out of gas.
The Takeaway
A preference assessment is the ultimate sign of respect for a child’s individuality. It tells the child, "I care about what you like, and I want to make our time together as rewarding as possible." By finding the right motivators, we turn therapy into a series of wins.