Preference Assessments

Reinforcement is a powerful tool that can support learning for individuals with autism. Reinforcing a student with items they like or prefer can motivate learners to complete tasks and learn new skills. Evidence-based preference assessments can help families and providers to identify motivating items or activities that support learning.

Preference Assessment Defined

A preference assessment is a way to determine what a student likes and how much they like it. Preference assessments may be informal, such as observing the student in the natural environment, or structured, such as a trial-based preference assessment. When several items are presented together, a formal preference assessment can identify a hierarchy of what the student prefers. Highly preferred items can be used to help teach difficult skills, including new social, language, and academic skills, while less preferred items can be used to help maintain a mastered skill.

Getting Started
Preference assessments can be conducted by anyone who knows the student! Family members, caregivers, teachers, support staff, and related service providers can complete preference assessments.
To Begin:

Talk to families and caregivers to find out what the student prefers at home.
Place items such as toys, games, and other materials around the room.
Observe and note the items and activities they interact with and how long they interact with them.

* During this kind of observation, items or activities are never taken from the student, and adult interaction should be kept to a minimum.

If the student seems to enjoy six items (e.g., Drawing materials, Puzzles, Listening to music, Slime, Favorite book, and Tablet time), those items and activities can be used to conduct a paired-choice preference assessment.

Conducting a Paired-Choice Preference Assessment

A paired-choice preference assessment identifies a hierarchy of what the student prefers. Rather than just placing all the items out on the table, this assessment limits each trial to just two items. Prepare for your paired-choice preference assessment by creating a chart with all the items that will be used, pairing them together in random order for 15 trials. Be sure that each item is paired with all other items at least once.

Paired-choice preference assessment chart should include:

The number of trials
The items and activities you are presenting
The side on which the item is presented (right or left)

*Noting the side of presentation is important because a student might simply be picking an item because it is closer to their dominant hand. If you notice that the student always chooses items on the same side, try changing the placement of that item to the other side of the student.

Sample Paired-Choice Preferred Assessment Chart

Trial	Right	Left	Trial	Right	Left	Trial	Right	Left
1	Puzzle	Tablet time	6	Drawing materials	Tablet time	11	Slime	Drawing materials
2	Favorite book	Slime	7	Drawing materials	Listening to music	12	Listening to music	Slime
3	Listening to music	Favorite book	8	Puzzle	Slime	13	Tablet time	Favorite book
4	Slime	Tablet time	9	Favorite book	Drawing materials	14	Listening to music	Tablet time
5	Puzzle	Favorite book	10	Listening to music	Puzzle	15	Drawing materials	Puzzle

Begin the paired-choice preference assessment:

Place the two items in your chart on a table or hold them up in front of the student.
Give the student an opportunity to select one of the items from the pair.
The student may select the item by reaching for it, pointing to it, using AAC (Augmentative and Alternative Communication), or by looking in the direction of the item (eye gaze).
Let the student engage with the selected item for 10-15 seconds and remove the other item.
While the student is engaging with the item, circle which item was selected in that trial.
After 10-15 seconds, gently remove the item.
Quickly present the next pair of items.
Repeat this cycle until all trials have been completed.

*If the student has difficulty relinquishing item(s), consider using alternative assessment methods that do not require removal of preferred items.

**Note: If the student does not indicate a choice or make a selection after presenting the two items for 5-10 seconds, then move to the next pair and do not circle either item on the chart.

Sample Results

The results of the example trials demonstrate the highest preferred item is the Slime (chosen 5 times), and the least preferred is the Puzzle (chosen 0 times). The most preferred items should be considered by educators to help motivate the student to learn more difficult or new skills. If aiming to maintain previously learned skills, then less preferred items could be utilized.

Troubleshooting

Item no longer appears to be a preference? -- For a student whose preferences seem to change frequently, a preference assessment may need to be completed daily or before each lesson. Preference assessments can be completed as often as necessary to determine the strength of motivators used to support the student’s learning.
No clear preference? -- Sometimes, a clear preference hierarchy is not identified during your initial trials. In addition to paired-choice preference assessments, there are several other methods that may offer valuable insights, though they often require more time, materials, and planning. If initial results are inconclusive, consider revisiting the student’s interests through naturalistic observation. Observing the student during free play, transitions, or leisure activities can help identify items or activities that naturally capture their attention.

References

Lill, J. D., Shriver, M. D., & Allen, K. D. (2021). Stimulus preference assessment decision-making system (SPADS): A decision-making model for practitioners. Behavior Analysis in Practice, 14, 1144-1156. https://doi.org/10.1007/s40617-020-00539-3
Wilson, S., Cividini-Motta, C., MacNaul, H., Salinas, R., & Ferrer, G. (2024). Preference for social stimuli: A comparison of stimulus modes used in preference assessments. Behavioral Interventions, 39(4), e2034. https://doi.org/10.1002/bin.2034