BA420 Unit 8 Alternating and Criterion Designs Paper Example

Two Ways to Practice Math Facts and Four Steps to a Longer Sit: A BA420 Unit 8 Alternating Treatments and Changing Criterion Paper

[Student Name]

Purdue University Global

BA420: Methods of Behavior Analysis

Unit 8 Alternating Treatments and Changing Criterion Paper

[Instructor Name]

[Date]

The writer, the school, the students and every data point are composite and illustrative; the articles and book cited are real.

Two Questions

Ruby, a seventh grader at the Wichita middle school where I work, is accurate but slow on multiplication facts. Her teacher wanted to know which of two practice methods would build her fluency faster: cover-copy-compare, in which Ruby looks at a fact, covers it, writes it from memory and checks, or timed practice with immediate feedback, in which she answers as many facts as she can in one minute and then reviews errors. Jaylen, a sixth grader, leaves his seat often during independent practice. His goal was to increase the time he stays seated, gradually, so that the expectation never jumped beyond what he could do and he could succeed from the first day.

The two questions called for different designs, and the district behavior analyst asked me to explain the choice to both teachers before data collection began. Ruby's question compares two interventions directly. Jaylen's involves a behavior that should change step by step.

Alternating Treatments for Ruby

Barlow and Hayes (1979) described the alternating treatments design as a strategy for comparing the effects of two or more treatments within a single participant. The treatments are alternated rapidly, often session to session, in a counterbalanced order, and each is associated with a distinct stimulus so the participant can discriminate between them. If one treatment consistently produces better results, its data path separates from the other's on the graph.

Ruby practiced one set of twenty facts with cover-copy-compare and a different, equally difficult set with timed practice. The two methods alternated daily in a predetermined order, with a blue folder for cover-copy-compare and a green folder for timed practice. Each day ended with a one-minute probe on both sets, scored by the teacher without knowing which method had been used that day.

Over sixteen school days, the two data paths separated clearly by the fourth session. Correct facts per minute on the timed-practice set rose from about twenty-two to forty-one; on the cover-copy-compare set, from about twenty-one to thirty. There was almost no overlap after the first week.

Ruby's two lines on one graph answered in three weeks a question that sequential phases would have taken a semester to answer.

Interaction Effects

Alternating treatments designs raise a concern: the effect of one treatment may carry over into the other, a problem called multiple treatment interference. Hains and Baer (1989) examined interaction effects in multielement designs and argued that such effects are inevitable to some degree, sometimes desirable because they reflect real conditions, and sometimes ignorable when they are small relative to the differences being compared. They recommended designing to minimize interference where it matters and interpreting results with it in mind.

For Ruby, interference was possible: timed practice might have made her faster on everything, including the other set. The team used separate fact sets to reduce this risk. The cover-copy-compare set still improved, which could reflect that method's own effect or some carryover. Either way, the difference between the two paths was large enough to answer the teacher's question, and timed practice became Ruby's main method for the rest of the semester.

Changing Criterion for Jaylen

Hartmann and Hall (1976) described the changing criterion design, in which an intervention is applied with a criterion for reinforcement that changes in steps. Experimental control is shown when behavior changes to match each new criterion, closely and repeatedly. The design especially suits behaviors that should change gradually, such as building tolerance or increasing work time.

Jaylen's baseline showed he stayed seated for an average of about four continuous minutes during independent practice. The intervention allowed him to earn a short movement break with a classroom job, such as delivering papers to the office, when he met the current criterion for continuous seated time. The criterion started at five minutes, then rose to eight, twelve and fifteen, each phase lasting at least four sessions and until his performance stabilized.

His data tracked each new criterion closely. In the five-minute phase, his longest continuous seated time each session ranged from five to seven minutes; in the eight-minute phase, from eight to ten; in the twelve-minute phase, from eleven to fourteen; and in the fifteen-minute phase, from fifteen to seventeen. The team also built in one brief return to the eight-minute criterion between the twelve and fifteen-minute phases; Jaylen's seated time dropped to match it, which strengthens the case that the criterion, not general improvement, was controlling his behavior.

Practical Lessons

Both designs taught the team something practical. For Ruby, the colored folders mattered more than expected: in the first session, before the folders were introduced, she mixed up which method went with which set, and her data for that day were discarded. Distinct stimuli are part of what makes an alternating treatments design work. For Jaylen, the hardest decision was when to raise the criterion. The district behavior analyst set a rule in advance: raise it after four sessions in which he met the current criterion, and never by more than a few minutes at a time. Setting the rule before the data came in prevented the team from raising the criterion on a good day and dropping it on a bad one, which would have muddied the demonstration of control. Jaylen also helped choose the movement-break jobs, which may explain why the breaks kept working for him across all four criterion phases.

Choosing Between Designs

The two cases show how the question shapes the design. Ruby's team needed to compare two treatments quickly with one student, which the alternating treatments design does well. Jaylen's team needed to change one behavior gradually, which the changing criterion design does well. Kazdin (2011) notes that each design has conditions under which it is strongest; neither would have suited the other student's question.

Conclusion

An alternating treatments design showed that timed practice built Ruby's math fluency faster than cover-copy-compare, with interaction effects weighed rather than ignored. A changing criterion design, with a brief return to an earlier criterion, showed that Jaylen's seated time followed each new goal. Barlow and Hayes, Hains and Baer, and Hartmann and Hall provide the logic for both designs, and the two students show why the question comes first.

References

Barlow, D. H., & Hayes, S. C. (1979). Alternating treatments design: One strategy for comparing the effects of two treatments in a single subject. Journal of Applied Behavior Analysis, 12(2), 199-210. https://doi.org/10.1901/jaba.1979.12-199

Hains, A. H., & Baer, D. M. (1989). Interaction effects in multielement designs: Inevitable, desirable, and ignorable. Journal of Applied Behavior Analysis, 22(1), 57-69. https://doi.org/10.1901/jaba.1989.22-57

Hartmann, D. P., & Hall, R. V. (1976). The changing criterion design. Journal of Applied Behavior Analysis, 9(4), 527-532. https://doi.org/10.1901/jaba.1976.9-527

Kazdin, A. E. (2011). Single-case research designs: Methods for clinical and applied settings (2nd ed.). Oxford University Press.