Office for People With Developmental Disabilities

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Conducting Preference Assessments on Individuals with Autism and other Developmental Disabilities

By Niall Toner MA, BCBA

New York State Institute for Basic Research in Developmental Disabilities
1050 Forest Hill Road
Staten Island, NY 10314
[email protected]

The Purpose of Preference Assessment

Many individuals with autism and developmental disabilities are not able to indicate their preferences and dislikes. However, because of the vast individual differences among people with autism and other developmental disabilities, caregivers cannot simply assume that our favorite things and activities may also be preferred by others. Things that are reinforcing or rewarding to one individual may be unpleasant for another person. Preference assessment aims to identify an individual’s favorite things so that they can be used as rewards or potential “reinforcers” of appropriate and desired behavior.

Increasing Desired Behavior

Reinforcement is any object, condition, or event that when presented immediately following a behavior, increases the frequency of that behavior. For example, if a boy being potty trained is given a favorite toy each time he uses the toilet, and we observe that he is using the toilet more now instead of going in his pants, then that toy is a reinforcer for appropriate behavior, in this case, using the toilet. The toy is said to be “reinforcing” that desired use of the toilet. However, if the same boy does not use the toilet more often despite being given a toy, then that toy fails to be a reinforcer. A different reward is needed. Reinforcement is the most effective method for increasing desirable behavior.

Most of us are well aware of our own likes and dislikes, as well as the preferences of our loved ones. Nonetheless, because reinforcement is the most effective way to increase desired behavior, it is helpful to conduct a preference assessment to be sure we know which of the person’s favorite things will be most useful as reinforcers, It is vital to identify a true preference instead of what we assume is someone’s preference. When caregivers choose to use a presumed preference, time, energy and resources will be lost if it is not a true preference (Cooper, Heron, & Heward, 2006). Imagine asking an individual with autism to perform an unpleasant task (such as having to sit quietly) and rewarding him with an undesirable object (like a piece of candy he dislikes). That may decrease compliance or even create a problematic behavior! Instead, using the most effective reinforcers will increase a person’s motivation to work for those reinforcers, which will yield a successful change in his or her behavior.

Types of Preference Assessments

Information about preferences can be gathered in three different ways: (1) Caregiver Interview, (2) Direct Observation; and (3) Systematic Assessment. Caregiver interview and direct observation methods are easiest for parents to use.

The caregiver interview is a quick and straightforward technique and can reduce the time and effort needed to gather information. It involves obtaining information from the individual’s parents, friends, and teachers (and from the individual, if communicative) by asking open-ended questions (e.g., “What does he like to do?”, “What are his favorite foods?”, and “Where does he like to go?”), followed by comparison questions (e.g., “Which does he like better, cookies or crackers?” and “What would he rather do, go for a walk or eat chips?”).

Another way to conduct caregiver interviews is to use surveys. One widely-used survey is the Reinforcement Assessment for Individuals with Severe Disabilities (RAISD, Fisher et al., 1994). This survey obtains information about potential reinforcers. It also ranks the potential reinforcers in order of preference. Although simple and time-efficient, using interviews alone can result in incomplete or inaccurate information. In fact, some studies have shown that, for the same individual, staff interviews did not reveal the same information as using a survey (Parsons & Reid, 1990; Winsor, Piche & Locke, 1994).

Using direct observation involves presenting the individual with free access to items you think he or she will like (presumed preferences) and recording the amount of time the person engages with an them. The more time spent with an item or activity, the stronger the presumed preference. During these observations, no demands or restrictions are placed on the individual. Direct observation usually results in more accurate information regarding preferences than interviews, but it will also require more time and effort.

Direct observations can be completed in an environment enriched with many of the person’s preferred items or in a naturalistic environment such as the person’s classroom or a room in their home. The individual is briefly exposed to all the predetermined items before the observation begins. During the observation, the amount of time the individual spends with each item or activity is recorded. In the naturalistic environment, the individual is observed during their free time in a natural, real-life setting. Again, the observer collects data on the length of time the person engages with each object or activity. Data are recorded over multiple days, and the total time spent on each object or activity will reveal the strongest preference.

The assessment method involves presenting objects and activities systematically to the individual to reveal a hierarchy or ranking of preferences. This method requires the most effort, but it is the most accurate. There are many different preference assessments methods, all of which fall into one of the following formats: single item, paired, and multiple choices (Cooper, Heron, & Heward, 2006).

Single item preference assessment (also known as “successful choice”) is the quickest, easiest testing assessment method. Objects and activities are presented one by one. Each item is presented several times in a random order. After each presentation, data are recorded on how long the person engages with each object or activity.

Paired method or “forced-choice” involves the simultaneous presentation of two items or activities. All items are paired systematically with every other item in a random order to ensure completeness. For each pair of items, the individual is asked to choose one. The most frequently selected item will likely be the most potent reinforcer. Since all objects and activities have to be paired together, this method takes significantly longer than the single method, but researchers found that the paired method was more accurate than the single item method (Pace et. al, 1985; Paclawskyj & Vollmer, 1995).

The multiple choice method is an extension of the paired method (DeLeon & Iwata, 1996). Instead of having two items to choose from, there are three or more. There are two variations to this method: with and without replacement. In the multiple choice with replacement method, when an object is selected, all other objects are replaced in the next trial. For example, if the individual is given a choice of cookies, crackers, and chips, and he chooses cookies, the cookies will be available for the next trial but the crackers and chips are replaced with new items. In the without replacement method, the cookies would not be replaced and the choice would only be between the crackers and chips. No new items would be available.


Conducting preference assessment to identify potential reinforcers is one of the first steps in managing the behaviors of individuals with developmental disabilities. Without a potent reinforcer, it will be difficult to change behavior. The methods discussed above can help you find out what reinforcers will work best for the individual you’re working with. Each method has its benefits and limitations, and using a combination of various methods is more advantageous than using one method alone. Moreover, preferences change over time and require continuous exploration. Therefore, assessments should be updated monthly or when an individual becomes tired of or bored with the preferred items. When selecting a preference assessment method, a practitioner or parent should consider the individual’s communication level, the amount of time available for the assessment, and the types of preferred items that will be available and useful. Remember: A preference assessment will yield a potential reinforcer, not a definite one. You will know for sure if a preference is a reinforcer if it increases the frequency of a behavior following each presentation.

Helpful Hints

  • Don’t mix Assessment Types: Conduct leisure item and food assessments separately because food tends to motivate people more than toys and other leisure items (Bojak & Carr, 1999; DeLeon, Iwata, & Roscoe, 1997).
  • Limit Access: It is important that the individual does not have free access to the items that are used as reinforcers. If music is a reinforcer, and the individual has music available all day long, then he is less likely to work for music. Music will lose its reinforcing value. Try to keep the reinforcer small (e.g., small bites of food) or brief (e.g., 5 minutes of watching TV).
  • Rotate and Vary Reinforcers: The items that act as reinforcers for the individual will change over time. Becoming bored with an item will decrease its usefulness as a reinforcer. Because of this it is important to rotate reinforcers so that the individual does not get tired of one reinforcer. For some individuals, less preferred, but varied reinforcers may be just as good as highly preferred, but unchanging reinforcers (Bowman et al., 1997). For those individuals who don’t find social attention such as spoken praise or positive interaction such as play motivating, begin pairing the rewards of toys and favorite activities with praise and social interaction (such as hugs or “high-fives”) as soon as possible. By association, praise and social interaction will gradually become reinforcing all by themselves.


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