How to Conduct Preference Assessments in ABA Settings

Conducting a preference assessment in ABA settings is essential for identifying items or activities that can act as effective reinforcers during therapy. In applied behavior analysis, selecting the right reinforcers is critical for teaching new skills and driving positive behavior change. Without meaningful reinforcement, clients are less likely to learn new behaviors or reduce challenging ones.

Why use a preference assessment in ABA

Effective reinforcement makes it more likely that a behavior will occur again. Thus, using reinforcers correctly is essential for helping clients learn important skills. Conducting preference assessments in ABA helps identify which items, activities, or experiences a person enjoys and will likely work as reinforcers.

Here’s why assessing client preferences is so important:

• Personalized reinforcement: An ABA preference assessment ensures rewards align with a client’s interests and motivation.
• Increase engagement: Clients participate more, learn new skills, and follow directions when strong reinforcers are used.
• Prevent overuse: If the same reinforcer is used too often, it may lose effectiveness. Regular assessments help find new options.
• Respect client choice: Preference assessments give individuals a voice in what they work for, making reinforcement more meaningful.
• Reduce problem behavior: Using preferred items or activities strategically can decrease challenging behaviors by providing access to enjoyable experiences.

When to use a preference assessment in ABA

Preference assessments in ABA should be conducted at multiple points throughout intervention to ensure reinforcers remain effective. Preferences can change over time, so ongoing assessment is essential for maintaining motivation and engagement.

• Frequency of assessments: For clients with stable preferences, weekly or monthly assessments may be sufficient. For individuals whose interests change frequently, assessments may need to occur daily or even hourly.
• Before starting intervention: Always conduct a preference assessment prior to beginning ABA programs to identify reinforcers for skill acquisition or behavior reduction.
• During skill acquisition: Use ABA preference assessments throughout, teaching new skills to confirm reinforcers are still motivating. If progress slows, reassess to find more effective options.
• Behavior reduction plans: Regular preference assessments help ensure alternative behaviors are reinforced strongly enough to replace challenging behaviors and prevent reinforcer satiation.
• Introducing new skills or demands: When new tasks are added, confirm reinforcers are current to reduce resistance and increase cooperation.
• Decline in motivation or progress: If engagement drops or progress plateaus, conduct an immediate preference assessment to identify new reinforcers.
• Transitions and generalization: Preference assessments are critical during major transitions (e.g., new school or home) and when generalizing skills to new settings or routines.

Types of preference assessments in ABA

Now they we have a better understanding of why and when to conduct preference assessments in ABA settings, let’s discuss the various types of preference assessments, how they work, and the advantages and disadvantages they can bring.

Indirect assessments

Indirect preference assessments in ABA are used to identify potential reinforcers for a client without direct interaction. These assessments can be conducted by casually observing the client or by interviewing them and their caregivers. Indirect methods also include structured tools such as questionnaires and surveys, which help gather information about items or activities the individual may find motivating.

Client interview

Client interviews are one of the most efficient ways to start a preference assessment in ABA. Asking the client directly about what they enjoy can quickly identify potential reinforcers. This method works best for individuals with at least moderate communication skills who can express their likes and dislikes.

Steps for conducting a client interview:

• Assess communication ability: Determine if the client can share preferences verbally or through alternative methods like pictures or apps.
• Ask clear, simple questions: Use open-ended prompts such as “What do you like to do for fun?” or structured questions like “Do you prefer playing with toys or watching videos?”
• Use reinforcer checklists: Provide a visual checklist with pictures of common reinforcers for the client to select.
• Rate preferences: Ask questions like “How much do you like coloring — just a little or a lot?”
• Observe non-verbal cues: Watch for facial expressions, tone, and body language when discussing different items.
• Summarize and analyze: Identify highly preferred items and look for patterns across categories such as social, sensory, or edible.

Advantages of client interviews:

• Gives the client a voice in their ABA intervention plan.
• Quick and easy to administer.
• Helps uncover preferences that may not be obvious through observation.

Disadvantages of client interviews:

• Clients may report liking something but not work for it.
• Preferences can change, requiring follow-up assessments.
• Limited effectiveness for individuals with minimal communication skills.

Caregiver interview

Caregiver interviews are a valuable indirect method for conducting preference assessments in ABA, especially when the client cannot communicate their preferences directly. This approach involves asking those closest to the individual — such as parents, teachers, or other caregivers — about what the client enjoys and finds motivating.

To conduct a caregiver interview preference assessment, do the following:

• Select the right caregiver: Choose someone who interacts regularly with the client and understands their likes, dislikes, and behaviors.
• Use structured questions: Ask open-ended or yes/no questions, such as:
  • What items, activities, or foods does the individual enjoy most?
  • Are there specific situations where certain items or activities are preferred?
  • What activities make them excited or happy?
• Ask about changes over time: Determine if previously preferred items are no longer reinforcing.
• Identify motivators for tasks: Find out what caregivers use to encourage compliance or task completion.
• Summarize and analyze responses: Compile potential reinforcers and look for patterns in preferred items or activities.

Advantages of caregiver interview preference assessments:

• Quick and easy to administer.
• Provides valuable insight for clients with limited communication skills.
• Helps identify reinforcers for use in direct preference assessments.

Disadvantages:

• Caregiver reports may be subjective or inaccurate.
• Preferences can change, requiring follow-up assessments.
• Some caregivers may not know all potential reinforcers.

Formal caregiver survey

Formal caregiver surveys and structured tools are an important part of indirect preference assessments in ABA. These instruments help gather detailed information from caregivers about an individual’s likes and dislikes, making it easier to identify potential reinforcers. Surveys are especially useful for recalling items and activities that could motivate the client.

Common structured preference assessment tools include:

• Reinforcer Assessment for Individuals with Severe Disabilities (RAISD): A structured interview where caregivers rate the likelihood that various items or activities will be reinforcing. RAISD helps identify preferred edibles, tangible items, sensory experiences, and social interactions.
• Reinforcement Inventory for Children and Adults: Assesses preferences across categories such as food, toys, entertainment, sports, music, excursions, social interactions, academics, domestic activities, and personal appearance.
• NCPMI Reinforcer Inventory: Provides a checklist for social, sensory, and activity-based reinforcers, along with questions about interests and dislikes.
• Custom inventories: ABA organizations or staff may create their own reinforcer checklists tailored to client needs.

Advantages of structured preference assessments:

• Quick and easy to administer.
• Useful for individuals with limited verbal communication.
• Provides insight from those who know the client well.
• Identifies broad reinforcement categories like sensory, edible, social, tangible, or activity-based.

Disadvantages:

• Subjective caregiver reports may not always reflect true client preferences.
• Does not directly measure reinforcement effectiveness — follow-up with a direct preference assessment is often needed.

Direct assessments

Direct preference assessments in ABA are systematic methods used to identify potential reinforcers for a client. These assessments involve presenting items or activities and recording the client’s choices or engagement levels. By observing how individuals interact with different options, ABA professionals can determine which stimuli are most motivating and likely to function as effective reinforcers.

Free operant

Free operant preference assessments in ABA involve observing a client in an environment where they have access to multiple potential reinforcers. This method allows the individual to interact freely with items or activities without interruption, making it ideal for clients who display challenging behavior when preferred items are removed.

The free operant method helps to identify which items or activities are most and least preferred. In this method, engagement time is a strong indicator of preference — longer interaction suggests higher motivation. Requests for more of an edible or to repeat an activity also signal strong preference.

Unlike other direct preference assessments in ABA, the free operant approach measures natural engagement rather than forced choices. It is considered a contrived assessment, whereas indirect observation occurs in the client’s natural environment.

How to conduct a free operant preference assessment:

• Arrange the environment with a variety of potential reinforcers, including novel items.
• Allow the client to explore without prompts or restrictions.
• Record how long they engage with each item.
• Note vocalizations, smiles, or excitement.
• Identify items with the longest engagement times as highly preferred reinforcers.

Pros and cons of free operant assessments

Advantages:

• Minimizes frustration and escape behaviors since items are not removed.
• Preferences can be ranked quickly.
• Simulates real-life choice-making.
• Useful for clients who avoid making choices.

Disadvantages:

• Does not capture moderate or low preferences.
• One highly preferred item may dominate, limiting variety in reinforcers.

Single stimulus

A single stimulus preference assessment, also referred to as a successive choice assessment, is a common method used in ABA therapy to identify potential reinforcers — especially for individuals who are unable to choose between multiple items or who display problem behavior when preferred items are removed.

This approach involves presenting one item at a time and observing the individual’s response. The client is allowed to interact with the item until they lose interest or stop engaging. While this method can take longer due to the need to assess each item individually, it provides valuable insight into what may serve as a reinforcer for clients with severe intellectual or developmental disabilities.

To carry out a single stimulus preference assessment in ABA, follow these steps:

• Select 5-10 potential reinforcers: These can include toys, snacks, sensory items, or social interactions. Choose reinforcers based on caregiver input, direct observation, or results from previous preference assessments.
• Present one item at a time: Allow the client to engage with each stimulus without competing options. Watch for interaction such as touching, holding, playing with, or consuming the item.
• Observe and record behavior: If the client does not interact with the item within 5 to 10 seconds, remove it and introduce the next item. Document behaviors such as:
  • Approaching or looking at the item
  • Picking up or physically interacting with the item
  • Actively playing with or consuming the item
  • Showing disinterest or turning away
• Repeat for each item: This process continues until all items have been presented individually.
• Analyze results: Although this method does not provide a clear preference ranking, you can use frequency or duration of engagement to loosely order preferences.

Pros and cons of single stimulus preference assessments

Advantages:

• Ideal for clients who struggle with making choices or exhibit challenging behavior during multi-item assessments.
• Easy to implement, requiring only one item to be presented at a time.
• Especially effective for individuals with developmental disabilities or limited communication skills.

Disadvantages:

• May overestimate preference strength, as there’s no competition between items.
• Does not establish a preference hierarchy.
• Engagement does not necessarily indicate reinforcer effectiveness — a client may interact with an item but may not be motivated to work for it.

Paired stimulus

Paired stimulus preference assessments are useful for people who can select items from an array of two. The goal is for the client to choose the most reinforcing items on each trial. It involves presenting two items at a time and asking the individual to choose one. It provides a ranked hierarchy of reinforcers.

Paired stimulus assessments are more accurate than single stimulus assessments because they force the client to choose between two items. This prevents them from selecting everything and helps to establish a level of preference for one item over another.

A paired stimulus preference assessment is conducted by following these steps:

• Select stimuli: Choose five to 10 items or activities that the individual might prefer. These are usually identified by caregivers, informal observation, or previous assessments.
• Pairwise presentation: Present two items at a time in a randomized or counterbalanced way to ensure every item is paired with every other item one time.
• Prompt the client to choose one of the items: Record what they choose.
• Present the item they chose with a different item: Record what they choose.
• Continue the trials: Make sure each item is paired together one time.
• If no selection is made: Repeat the trial. Record as a non-selection if they do not choose one on the repeated trial.
• Calculate preference rankings: For each stimulus, divide the number of times it was chosen by the total number of trials it was presented in, then multiply by 100 to get percentage of trials selected. Rank the stimuli from highest to lowest based on their percentage. The stimulus with the highest percentage is the most preferred.

Pros and cons of paired stimulus assessments

Advantages of paired-stimulus assessments include:

• Creating a clear reinforcer preference ranking.
• Helping avoid overestimating preferences for items that are just available rather than being truly reinforcing.
• Work well when clients can understand and select between two options.
• More accurate than using informal caregiver reports.

Disadvantages of paired-stimulus assessments include:

• They can be time-consuming.
• If an individual does not reliably select between two items, another method may be better.
• They may lead to problem behavior if the non-chosen item is removed.

Multiple Stimulus Without Replacement

A Multiple Stimulus Without Replacement (MSWO) preference assessment is a widely used method in ABA therapy for identifying a client’s most preferred items or activities. Unlike single stimulus methods, MSWO presents multiple options at once, and as each item is selected, it is removed from the array in the next round. This process results in a clear preference ranking, which can inform more effective reinforcement strategies.

MSWO is one of the most efficient and reliable direct preference assessments available and is praised for its ability to quickly determine which items are most motivating to a client. However, it may not be suitable for individuals who have difficulty making choices or who become distressed when preferred items are taken away. When used appropriately, MSWO assessments can be strong predictors of reinforcement effectiveness.

Follow these steps to complete an MSWO assessment:

• Select 5-7 potential reinforcers: Items might include snacks, toys, sensory materials, or other preferred activities based on caregiver input or past assessments.
• Arrange the items in an array: Place them in a line or semi-circle so the client can see and easily reach each option.
• Use a temporary barrier: Before each trial, place a small barrier in front of the items and remove it to cue the client that it’s time to make a choice.
• Prompt the client to choose: Use a simple instruction like, “Pick one.”
• Allow engagement: Once the client selects an item, let them interact with it briefly. Then remove the item from the array.
• Reshuffle and repeat: Rearrange the remaining items and continue the process until the client no longer makes a choice or all items have been selected.
• Rank preferences: The first item chosen is typically the most preferred, while the last selected — or not selected — item is the least preferred.

Pros and cons of MSWO preference assessments

Advantages:

• Efficient and structured, helping identify preferences in a short time.
• Reduces frustration by not replacing selected items.
• More accurate than single-stimulus methods, as it avoids preference overestimation.
• Highly predictive of reinforcer effectiveness, making it valuable for behavioral intervention planning.

Disadvantages:

• Not ideal for clients with decision-making difficulties or those who choose impulsively.
• Some individuals may struggle with item removal, potentially leading to problem behaviors.
• May not capture interest in novel stimuli, especially if only familiar items are presented.

Multiple Stimulus With Replacement

A Multiple Stimulus With Replacement (MSW) preference assessment is a valuable tool in ABA therapy for identifying potential reinforcers — particularly for clients who exhibit challenging behaviors when preferred items are removed. While it follows a similar structure to the MSWO assessment, the key distinction is that the selected item is returned to the array in the next trial.

MSW assessments are designed to reduce frustration while still collecting meaningful data about reinforcer preferences. This approach is especially useful for individuals who have difficulty tolerating item removal or who cannot complete longer assessments.

Follow these steps to perform an MSW preference assessment:

• Choose 3-4 potential reinforcers: Select varied items — such as toys, foods, or sensory materials — that differ in function, texture, or flavor to better assess preference diversity.
• Present the items in an array: Place them in a line within the client’s visual and physical reach.
• Use a temporary barrier: Signal the start of each trial by removing the barrier, helping to cue the client.
• Prompt a choice: Use a simple instruction like, “Pick one.”
• Allow engagement: Let the client interact with the selected item briefly, then take it back and return it to the array.
• Shuffle item positions: Rearranging items between trials helps reduce position bias and encourages item-based choices rather than location-based ones.
• Repeat for 5-10 trials: Tally how often each item is selected.
• Analyze the results: Items chosen more frequently across trials are likely to function as effective reinforcers.

Pros and cons of MSW preference assessments

Advantages:

• Quicker than paired-stimulus assessments, allowing multiple options to be evaluated simultaneously.
• Returning items helps minimize frustration and reduce problem behaviors during the assessment.
• Well-suited for clients who may not tolerate item removal or who struggle with lengthy assessments.
• Frequent selection of an item may indicate strong reinforcement value.

Disadvantages:

• Some individuals may fixate on a single item, choosing it repeatedly and ignoring other options.
• Does not generate a comprehensive preference hierarchy like MSWO assessments.

May produce inaccurate results for clients with perseverative behaviors, as habitual selection may not reflect true preference.