To randomize changing-criterion schedule elements, use a procedure developed for that design and reviewed by a qualified methodologist. Predeclare criterion values, step order, allowable phase lengths or timing patterns, reinforcement and safety rules, and the complete assignment set. Select the schedule prospectively, preserve delivered steps, and use the matching test. A phase-design or alternating-treatment randomization cannot simply be relabeled for changing criteria.
Select a design-specific procedure
Name the published randomization method and exact version. Verify its assumptions, permissible schedules, statistic, and software with a qualified reviewer.
Predeclare criterion values and timing
Separate what is randomized from what stays fixed. Document steps, phase lengths, direction, reinforcement, mastery, and safety rules.
Enumerate complete schedules
Generate only sequences allowed by the chosen changing-criterion procedure and the clinical plan. Preserve their probabilities.
Record selected and delivered steps
Keep every planned criterion, timing point, actual change, pause, regression, and reason. Welfare decisions take precedence over schedule adherence.
Integrate tracking and inference
Report criterion-response correspondence, trend, variability, overlap, step replication, original-unit magnitude, and the matching randomization result.
Build Sol's criterion-step randomization plan
For the randomize changing-criterion schedule question, start with a locked protocol and a versioned criterion-step randomization plan. Record Sol's design, setting, randomization unit, complete schedules, constraints, assignment probabilities, draw, selected schedule, delivered schedule, statistic, tail, tie and missing-data rules, software, and reviewers. Link each schedule position to the original time-series record. The file should let an independent analyst reconstruct randomized changing-criterion schedule without guessing what was possible before outcomes.
Work the schedule example for Sol
Sol's fictional plan uses rising criteria and four preapproved timing vectors for three changes: (5,10,15), (6,10,14), (5,11,16), and (6,12,16). The criterion values remain fixed; only their change times vary under this illustrative scheme. A draw selects one vector before outcomes, subject to the plan's health and assent gates. Show the schedule generator, inclusion tests, probability calculation, draw evidence, and selected sequence at full precision. This fictional example illustrates a prospectively varied step schedule; it does not establish a universal phase length, alpha, power level, or treatment plan.
Audit Sol's assignment evidence
Sol's plan identifies the specific changing-criterion procedure, four vectors, fixed criterion values, step-size rationale, timing probabilities, random draw, selected and delivered vector, decision statistic, and software implementation. A methods reviewer verifies the scheme against its source. The audit also checks timestamps, protocol amendments, allocation concealment when applicable, cancellations, replacements, missing positions, phase labels, probability totals, software version, and whether the analysis generator matches the design generator. Unresolved discrepancies stay on hold.
Prevent the assignment error in Sol's review
Recent changing-criterion randomization proposals are not interchangeable. Sol's team avoids inventing a hybrid formula from a reversal or AB test and keeps the page educational until design-specific review is complete. Randomization means chance operated at the named assignment step under the documented scheme. Varied, alternating, staggered, or response-guided schedules are not automatically randomized.
Integrate design and visual evidence for Sol
Visual analysis examines whether responding tracks criterion changes, whether steps are large enough to detect and small enough to be feasible, and whether bidirectional or replicated steps add evidence. Sol's preferences, effort, health, and burden remain part of every progression decision. The WWC Version 5.0 handbook is a research-review standard, not a universal clinical protocol. Review the graph, level, trend, variability, immediacy, overlap, consistency, measurement quality, assignment fidelity, original-unit magnitude, and every planned replication.
Protect Sol's participation
The randomized changing-criterion schedule never outranks Sol's welfare. Keep augmentative and alternative communication, interpreters, mobility, food, water, bathroom use, prescribed care, health support, rest, relationships, and emergency help available. Use accessible consent and assent processes and honor withdrawal or distress. If safety, medical need, access, or choice changes the schedule, qualified people act and document the design consequence.
Use design-specific sources for Sol
For Sol's a prospectively varied step schedule, the BACB ethics hub and CASP public summary provide professional context, and the BCBA Test Content Outline identifies examination content on measurement and single-case design. A randomized SCED overview covers phase and alternation schemes. Research on multiple-baseline power, rapid alternation, and changing-criterion randomization shows design-specific behavior. A health-sciences methods paper discusses randomized phase, alternation, and case-placement options. Nonconcurrent multiple-baseline research addresses assignment and design-quality issues. ASHA supports continuous AAC access.
Rehearse Sol's schedule before collecting outcomes
Before the home exercise-duration study begins, Sol's team runs the criterion-step randomization plan with fictional schedules and outcomes. The rehearsal checks the earliest and latest permissible assignment, probability totals, selected-schedule trace, delivered-schedule fields, statistic, missing-data behavior, and a hand-worked reference result. Reviewers store test cases, expected outputs, code version, and correction log. The dry run can repair mechanics before outcomes; it cannot use Sol's future data to change the assignment scheme.
Define Sol's stop, pause, and amendment rules
Sol's protocol names who may stop or pause the randomized changing-criterion schedule, which health, safety, assent, access, staffing, technology, or feasibility events trigger action, and how urgent care proceeds. It separates an immediate protective action from a later research amendment. Any amendment receives a new version, date, rationale, approval path, and prospective assignment set; the original schedule and data remain intact. The team also tells Sol how to withdraw or raise a concern through an accessible route. These rules make the humane response predictable and keep a necessary change from being hidden as ordinary schedule variation.
Close Sol's design review
Review the criterion-step randomization plan with Sol, the responsible clinician, and a statistician or methodologist familiar with the exact design. Preserve protocol, schedule set, probabilities, draw, selected and delivered sequence, raw data, graph, code, outputs, deviations, inference limits, client input, and decisions. Keep the page draft and noindex until every named review is complete.
Related resources
- How to Randomly Assign Cases to Fixed Multiple-Baseline Staggers
- How to Randomize Phase-Change Points in a Reversal Design
- How to Handle Unequal Assignment Probabilities in a Single-Case Randomization
- How to Build a Restricted Randomization Set for Alternating Treatments
Sources
- Behavior Analyst Certification Board, Ethics Information and Ethics Codes
- Council of Autism Service Providers, ABA Practice Guidelines Version 3.0 public summary
- Behavior Analyst Certification Board, BCBA Test Content Outline, 6th edition
- What Works Clearinghouse Procedures and Standards Handbook, Version 5.0
- Randomized Single-Case Experimental Designs in Healthcare Research: What, Why, and How?
- Power of a Randomization Test in a Single Case Multiple Baseline AB Design
- Randomization Tests for Single Case Designs with Rapidly Alternating Conditions
- Type I Error Rates and Power of Two Randomization Test Procedures for the Changing Criterion Design
- Randomized Single-Case Intervention Designs and Analyses for Health Sciences Researchers
- Examining and Enhancing the Methodological Quality of Nonconcurrent Multiple-Baseline Designs
- American Speech-Language-Hearing Association, Augmentative and Alternative Communication