Task interspersal and a high-probability request sequence can both alternate easier and harder actions, yet their usual structures differ. Task interspersal distributes task types across a teaching session to support acquisition or practice. A high-probability sequence presents several frequently completed requests immediately before a lower-probability request. The terms can overlap in practice, so the team should name the exact sequence, purpose, consequences, data, and client safeguards.
Compare task interspersal vs high-probability sequence
Task interspersal usually asks whether mixed practice changes acquisition, maintenance, preference, or session performance. That brief sequence usually asks whether a lead-in changes responding to the next request. Record the actual arrangement instead of relying on either label.
Look at spacing
A teaching mix may place maintenance trials throughout many acquisition trials. The high-probability lead-in requests cluster immediately before one later request. Either procedure can vary, which makes timing and trial order essential fields.
Use evidence in scope
The provider task-interspersal survey found broad procedural variation. The object-label study compared constant, similar-interspersal, and dissimilar-interspersal teaching. The BACB outline supplies measurement and antecedent-intervention scope without making the two procedures synonyms.
Preserve client protections
The Ethics Code addresses understandable communication, involvement, assent when applicable, risk, and evaluation. ASHA supports continual AAC access. Neither label authorizes pressure, blocked exits, or loss of basic access.
A practical example
Omar receives one maintained matching trial after every two new reading trials across a session. That is documented as task interspersal. Before one unfamiliar community step, Omar also chooses two familiar actions. That brief cluster is recorded separately as a high-probability sequence.
Questions families can use
Are tasks distributed or clustered? Is the goal acquisition, maintenance, preference, or the next-request result? Which requests were screened? Which data belong to each procedure? Can the person pause or decline?
Sources
- Behavior Analyst Certification Board, BCBA Test Content Outline, 6th edition
- Bottini and colleagues, Task Interspersal Implementation Practices With Individuals With Autism Spectrum Disorder
- Volkert and colleagues, An Exploratory Analysis of Task-Interspersal Procedures While Teaching Object Labels
- Grow and LeBlanc, Designing Receptive Language Programs
- Behavior Analyst Certification Board, Ethics Code for Behavior Analysts
- American Speech-Language-Hearing Association, Augmentative and Alternative Communication
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