Single stimulus preference assessment
In a single stimulus preference assessment, items are presented one at a time, and the person's approach or engagement with each item is recorded.
Also called a successive choice assessment, this format presents one item on each trial. The RBT records whether the client approaches, reaches for, takes or engages with the item within a set time, and sometimes how long they engage with it. Each item is presented several times, and the percentage of trials with approach is calculated.
Single stimulus presentation is useful for clients who cannot yet scan and choose between two or more items, such as some young children or clients with significant physical or intellectual disabilities. It requires only a response to a single item.
Its limit is that no item competes with any other. A client may approach almost everything offered, so many items look highly preferred and the results do not distinguish strong from moderate preferences. In other words, the method can overestimate preference. Supervisors may use it as a starting point or for clients who cannot do other formats.
Example and non-example
| Example | An RBT holds out a vibrating toy to an adult client for 10 seconds and records whether they reach for it, then later presents a soft blanket, then music, one item at a time. |
|---|---|
| Non-example | Offering the vibrating toy and the blanket together and recording which one is chosen is a paired stimulus assessment. |
Don't confuse it with
| Paired stimulus preference assessment | Single stimulus presents one item per trial; paired stimulus presents two items and requires a choice. |
|---|---|
| Free operant preference assessment | Single stimulus offers items one at a time; free operant offers all items together and times engagement. |
Test yourself
-
Question 1In which preference assessment are two items presented at a time and the client chooses one of them?
Show answer
D: Paired stimulus. In a paired-stimulus (forced-choice) assessment, items are presented two at a time, and each item is paired with every other item. The client's choices are used to rank the items.
- A: Single-stimulus assessment presents one item at a time.
- B: MSWO presents an array of several items at once.
- C: A free-operant assessment makes all items available at the same time with no trials.
Task B.1 · 40-hour curriculum section D
-
Question 2A supervisor asks an RBT to present a client's items one at a time and record whether the client reaches for or engages with each one. Which preference assessment is this?
Show answer
C: Single stimulus. In a single-stimulus assessment, items are presented one at a time and the RBT records approach or engagement. It does not require the client to choose between items.
- A: MSWO presents several items in an array.
- B: A free-operant assessment makes all items available together.
- D: A paired-stimulus assessment presents two items per trial.
Task B.1 · 40-hour curriculum section D
-
Question 3In a single-stimulus assessment, a client approaches and plays with every item presented. What is the main limitation of these results?
Show answer
B: They do not show which items are preferred over others. Because items are not compared directly, a client who approaches everything gives little information about relative preference. Choice-based formats such as paired stimulus or MSWO rank items.
- A: Approaching items suggests they may be preferred, not that they will fail as reinforcers.
- C: Approaching every item does not indicate an implementation error.
- D: Satiation would usually reduce approach, not produce approach to everything.
Task B.1 · 40-hour curriculum section D
Answer every question to see your score.
On the RBT exam
This term belongs to task B.1 Preference assessments in content area B, Behavior Assessment, which is 8 of the 75 scored questions.