This comparison draws in part from “Technician WORKSHOP #1: You Can Have Whatever You Like: Understanding Preference Assessments and Incorporating Them Into Your Practice” by Rachel Peters, M.S., BCBA (BehaviorLive), and extends it with peer-reviewed research from our library of 27,900+ ABA research articles. The decision framework, BACB ethics code references, and cross-links below are synthesized by Behaviorist Book Club.
View the original presentation →When a BCBA or behavior technician needs to generate a preference hierarchy — a rank ordering of items from most to least preferred — two structured assessment formats are most commonly used: paired stimulus (forced choice) and multiple stimulus without replacement (MSWO). Both produce preference hierarchies, but they differ in administrative efficiency, precision, and practical application across item set sizes and populations. Understanding the tradeoffs between these formats helps practitioners select the approach that best fits the clinical situation and the individual being assessed.
| Factor | Evidence-Based Approach | Traditional Approach |
|---|---|---|
| Presentation format | Paired stimulus: Two items presented simultaneously; individual selects one | MSWO: All items presented simultaneously; individual selects sequentially as items are removed |
| Number of trials required | Paired stimulus: Increases rapidly with item set size — n(n-1)/2 trials for n items | MSWO: Fewer trials for large item sets; one pass through the item set produces a complete hierarchy |
| Precision of output | Paired stimulus: Percentage selected per item — precise ranking even for items of similar preference strength | MSWO: Sequential selection order — clear hierarchy, but less precise for items of similar preference strength |
| Best suited for | Paired stimulus: Small item sets (3-8 items), situations requiring precise differentiation between similar-preference items | MSWO: Larger item sets (5+ items), routine clinical preference assessment when efficiency is a priority |
| Individual factors | Paired stimulus: May be easier for individuals who are overwhelmed by large arrays | MSWO: May be challenging for individuals who cannot tolerate having items removed from the array |
| Clinical application | Paired stimulus: Building a reinforcer menu for a new skill program requiring precise hierarchy | MSWO: Routine assessment for ongoing sessions and monitoring changes in preference over time |
The ABA Clubhouse has 60+ on-demand CEUs including ethics, supervision, and clinical topics like this one. Plus a new live CEU every Wednesday.
Use this framework when approaching technician workshop #1: you can have whatever you like: understanding preference assessments and incorporating them into your practice in your practice:
Does the data support a need for intervention? Is there a meaningful impact on the individual's quality of life, safety, or access to reinforcement?
YES → Proceed to assessment NO → Document reasoning, monitor
A functional assessment should guide intervention selection. Avoid defaulting to standard protocols without individual analysis. Consider environmental variables, setting events, and private events.
YES → Select evidence-based approach matched to function NO → Complete assessment first
Goals should be co-developed. Assent and informed consent are ethical requirements. The individual's preferences and values matter in selecting both goals and methods.
YES → Proceed with collaborative plan NO → Engage in shared decision-making
This course covers the clinical and ethical dimensions in detail with structured learning objectives and CEU credit.
Technician WORKSHOP #1: You Can Have Whatever You Like: Understanding Preference Assessments and Incorporating Them Into Your Practice — Rachel Peters · 0 BACB General CEUs · $0
Take This Course →We extended this decision guide with research from our library — dig into the peer-reviewed studies behind each approach, in plain-English summaries written for BCBAs.
280 research articles with practitioner takeaways
279 research articles with practitioner takeaways
258 research articles with practitioner takeaways
BACB General CEUs · $0 · BehaviorLive
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Research-backed answers for behavior analysts
All behavior-analytic intervention is individualized. The information on this page is for educational purposes and does not constitute clinical advice. Treatment decisions should be informed by the best available published research, individualized assessment, and obtained with the informed consent of the client or their legal guardian. Behavior analysts are responsible for practicing within the boundaries of their competence and adhering to the BACB Ethics Code for Behavior Analysts.