Teaching runs on reinforcement, and you cannot reinforce with something the learner does not care about. A preference assessment is how the team finds out, with data instead of guesses, which items and activities a learner is most likely to work for.
Why it matters
A learner who earns a sticker they do not care about has little reason to keep responding. When the items you deliver are things the learner actually wants, skills are learned faster and sessions go more smoothly. Preferences also change: a favorite toy on Monday may be boring by Thursday, so preference assessments are repeated, sometimes briefly at the start of every session.
Your supervisor chooses the method and the items. As an RBT, you will often run the assessment and record the results. On the exam, expect short scenarios: an RBT presents items in a certain way and you name the method, or you pick the method that fits a learner's needs.
Key ideas
- Preferred is not the same as reinforcing. A preference assessment identifies items that are likely to work as reinforcers. Only seeing behavior increase when the item follows it shows that the item actually functions as a reinforcer. That check is called a reinforcer assessment.
- Ask, observe, or test. Teams may start by asking the learner or caregivers what the learner likes (an interview or survey). Then they observe what the learner does with free access to items, or run trial-based assessments where the learner chooses among items presented in a set way.
- Let the learner sample first. Before trials begin, give brief access to each item so the learner knows what is on offer.
- Give brief access after each choice. After a selection, the learner gets the item for a short, set time (or a small bite of an edible), and then the next trial starts.
- Rank the results. Trial-based methods produce a preference hierarchy: items ranked from most to least selected, often as a percentage of the trials in which each item was offered.
- Motivation matters. A learner who just ate lunch may choose snacks less often. Motivating operations like this are one reason results change and assessments are repeated.
Definitions
- Paired-stimulus (forced-choice) assessment: two items are presented at a time and the learner picks one. Each item is paired with every other item, and items are ranked by how often they were chosen. It gives a clear ranking but usually takes longer than MSWO or free-operant.
- Multiple-stimulus without replacement (MSWO): several items (often 5 to 8) are presented in a row or array. The chosen item is not put back; the remaining items are rearranged and offered again until all are chosen or the learner stops choosing. It is faster than paired-stimulus.
- Multiple-stimulus with replacement (MSW): the chosen item is put back in the array each trial, and the items not chosen are swapped for new ones. Top items keep showing up, so lower-ranked items get less information.
- Free-operant preference assessment: the learner has free access to all the items at once for a set time, and you record how long they engage with each one. Nothing is removed, which makes problem behavior less likely. One limit: a learner may spend the whole time with one favorite, so the other items may not get ranked.
- Single-stimulus assessment (also called successive choice): one item is presented at a time, and you record whether the learner approaches or engages with it. Useful for learners who have trouble choosing between two or more items.
Examples from a session
Three methods, three learners
- Paired-stimulus: At a clinic, Jordan (age 4) is offered a bubble wand and a toy car side by side. He reaches for the car and plays with it for about 20 seconds. Then the RBT presents the next pair. By the end, each of the five items has been paired with every other item once.
- MSWO: At school, Priya (age 9) sees six items in a row on her desk. She picks the tablet, uses it briefly, and the RBT sets it aside. The remaining five are rearranged and offered again, and so on until every item is chosen.
- Free-operant: At home, Marcus (age 15) has access to a basketball, headphones with music, a puzzle, and drawing supplies for 5 minutes. The RBT does not prompt or take anything away and records how many seconds he spends with each item.
In each case, the RBT follows the procedure the supervisor wrote, records data as each choice happens, and shares the results so the supervisor can choose which items to use during teaching.
Common mistakes / exam traps
- Leaving items in the same spot. Some learners tend to choose from one side. Rearranging items between trials keeps position from driving the results.
- Treating one assessment as permanent. Preferences shift with satiation, deprivation, and time. Results from last month may not apply today.
- Reading a mixed array as dislike. When snacks and toys share one array, snacks are often chosen first and push toys down the ranking, so a low-ranked toy may still be well liked.
- Calling a preferred item a reinforcer too soon. Being chosen often shows preference; showing that the item strengthens behavior confirms a reinforcer.
- Choosing items on your own. Use the items and procedure your supervisor selected. Suggest new items to your supervisor if you notice the learner enjoying something that is not on the list.
Exam trap
MSWO vs. MSW: in MSWO (without replacement), the chosen item leaves the array, so every item gets ranked. In MSW (with replacement), it goes back in, so one favorite can be picked on every trial.
Exam trap
If a question describes a learner who engages in problem behavior when items are removed, look for the free-operant assessment. Nothing is taken away, so it is less likely to set off that behavior.
Quick check
An RBT places five toys in front of a learner. After the learner picks one and plays with it briefly, the RBT sets that toy aside and rearranges the remaining four before the next trial. Which assessment is this?