The number of matrix training exemplars should come from component knowledge, matrix size, the selected diagonal or overlap arrangement, baseline performance, valid exposure, probe results, time, access, and the person's experience. One diagonal may be an efficient starting test when prerequisites are strong. Additional component or overlap teaching may be needed, and every new phase should preserve remaining probe cells.
Choose an exemplar set
Count components, possible combinations, usable cells, baseline-known cells, directly taught cells, and reserved probe cells. Confirm that each taught exemplar contributes useful component coverage and that the resulting response is meaningful.
Avoid counting cells as equal doses
A 4 by 4 matrix contains 16 combinations, yet teaching four cells can involve very different trials, prompts, session time, and component histories. Report actual teaching opportunities and mastery evidence for each exemplar.
Use research as a starting boundary
The tutorial describes nonoverlap and overlap selection options. The comparison study found different best-performing arrangements across three participants, so no fixed exemplar count follows from that experiment.
Track burden and access
The Ethics Code addresses client involvement, assent when applicable, risk, and data-based evaluation. ASHA supports communication access. Added exemplars should have a defined benefit, stop rule, and accessible response.
A practical example
A 4 by 4 grid has 16 usable cells. Eli masters four diagonal exemplars, then answers 7/12 held-out probes. The team teaches four overlapping exemplars and later probes the eight cells still untouched, rather than reusing the original denominator.
Questions families can use
How many cells exist? Which exemplars cover each component? How much direct teaching occurred? Which cells remain clean probes? What result triggers expansion, direct teaching, or closure?
Sources
- Behavior Analyst Certification Board, BCBA Test Content Outline, 6th edition
- Curiel and colleagues, A Tutorial for Implementing Matrix Training in Practice
- Curiel and colleagues, Matrix Training for Expanding the Communication of Toddlers and Preschoolers With Autism Spectrum Disorder
- Niland and colleagues, Comparing Matrix-Training Procedures with Children with Autism Spectrum Disorder
- Frampton and colleagues, The Use of Matrix Training to Promote Generative Language with Children with Autism
- Simeone and colleagues, Miniature Linguistic Systems for Individuals With Autism Spectrum Disorder: A Systematic Review and Meta-Analysis
- Behavior Analyst Certification Board, Ethics Code for Behavior Analysts
- American Speech-Language-Hearing Association, Augmentative and Alternative Communication
Finni resources
