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What Are Preference Assessments in ABA?


What motivates you? I know for myself any kind of hazelnut chocolate is a favorite. But what happens when I am sick of chocolate or I have just eaten? I have my backup motivators – like instagram, reality tv, a good massage… Not everyone can tell us what motivates them, and sometimes what we think will motivate us does not do the trick. This is why we have preference assessments.

What is a Preference Assessment?

A preference assessment is a tool used to guide practitioners in providing reinforcement to a client to increase the future probability of a behavior. Plainly, a preference assessment tells us what will motivate an individual at a specific point in time.

When a client engages in an appropriate response, they then receive some form of reinforcement. It should be provided contingent on their response in order to increase the future likelihood of that response. A preference assessment guides the practitioner in determining which stimuli will act as a reinforcer to increase future behavior. Conducting a preference assessment will tell us under which conditions (such as tasks, states of deprivation, or reinforcement schedules) the preferences are most valuable. Preference assessments are a key component for pairing sessions.

We have a checklist of common reinforcers that you can use to get started finding out your learners’ preferences! Download it for free below!

The Three Types of Stimulus Preference Assessments:

For all types of Stimulus Preference Assessments, be sure to present stimuli from various sensory systems (e.g. tactile, visual, auditory, etc.), and present them in randomized order.


You can ask the target individual for their preference, depending on their communication style and level. Asking can be in the form of interviews and questionnaires, or visuals with pictures of the items/activities. You can use open-ended questions such as, “What toys do you like to play with during your free time?” or a choice format where the individual picks between options such as, “Would you like chocolate or the race car?”. Or they can rank preferences in order such as from most preferred to least preferred. These are all ways to ask about stimulus preferences.

Asking significant others is also an important resource to use. Just adapt the same types of questions for the target individual for the significant other to answer. Significant others include parents, teachers, siblings, other close family members, or others.

Offering a pre-task choice, such as asking, “What do you want to earn for doing this task?” is another form of asking about preferences.

Free-Operant Observation

Free-operant observation allows the target individual to have unrestricted access to various items and activities, and the practitioner observes and records. The individual is free to navigate the items. 

Contrived free-operant observation is where the practitioner sets up an environment with items of probable reinforcing value. We determine these items through interviews and/or questionnaires with the target individual and significant others. When the target individual explores the items in the environment, the practitioner takes data on the total duration of time the individual engages with the item.

Naturalistic free operant observation occurs in the target individual’s natural environment, without the practitioner including additional stimuli. As with the contrived free-operant observation, the practitioner watches and records the learner’s behavior and total duration with items.

The longer the duration with a particular item, the higher the preference value is given.

Types of Stimulus Preference Assessments

Trial-Based Methods

Where the free-operant observation entailed the learner taking the lead and exploring items naturally, the trial-based methods include a more active role on behalf of the practitioner. We present stimuli in trials and then record data on responses.

The single stimulus method is when one item is presented at a time. This style of preference assessment is perfect for the learner who has difficulty choosing between two or more stimuli. We record the reaction of the target individual, such as if they approached or moved away from the item, and record data on the total duration of engagement with the stimulus.

Paired stimuli, commonly referred to as forced choice, are presented two at a time to the target individual. Individual stimuli are paired with every other stimulus in a set and presented randomly. We record their choice of one item over another as well as how many times a single item is chosen.

The multiple stimuli method is similar to the paired stimuli method. However, instead of pairs of 2 stimuli, we present an array of 3 or more. This is a quicker method as more stimuli are presented at a single time.

Multiple stimuli with replacement is where the item that is chosen stays in the array for the next set, and the unchosen items are replaced. Multiple stimuli without replacement is when the chosen item is removed from the set, and the following trial occurs with the remaining stimuli.

How To Run Preference Assessments

Any preference assessment is a two-step process. Compile multiple stimuli that are potential reinforcers and then present them to the target individual using one of the above mentioned methods. And as always, data data data.

Don’t forget to download our free reinforcement checklist!

3 thoughts on “What Are Preference Assessments in ABA?”

  1. Pingback: ABA Pairing - How to ABA

  2. Pingback: Beginner Requesting - How to ABA

  3. Pingback: preference assessment data sheet - konkeng & konkeng

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