Application of Multiple Baseline Designs

1. Application of Multiple Baseline Designs Single Subject Research (Richards et al.) Chapter 8

2. Multiple Baseline Across Behaviors Design Hargrove, P. M., Roetzel, K., & Hoodin, R. B. (1989). Modifying the prosody of a language-impaired child. Language, Speech, and Hearing Services in the schools, 20, 245-258.

4. Across Behaviors Design • The intervention was sequentially applied as the criterion level of performance was met on the preceding target behavior. • Treatment was also discontinued with a target behavior once criterion was achieved. Why using an across behaviors design for this study? • Permits performance on the three speech parts (subjects, verbs, objects) to be treated as separate variables. • The lack of covariance among the targeted responses before implementation of the training procedure strengthens the argument for internal validity.

5. Limitations of the Study • The lack of identification of the training components or combination of components that might have been responsible for changes (loose training). • The gains were not fully maintained. suggestions includes implementing a longer training phase, more vigorous criterion, or addition of a maintenance phase.

6. Multiple Baseline Across Subjects Design Yoder, P. J., Yarren, S. F., Kim, K., & Gazdag, G. E. (1994). Facilitating prelinguistic communication skills in young children with developmental delay: II. Systematic replication and extension. Journal of Speech and Hearing Research, 37, 841-851. • This section is focused only on the first hypothesis among 3.

8. Across subjects Design • The researchers used abrupt changes in the level of responding and slope of the data path as indicators of intervention effects rather than a specific criterion level to determine when to implement the intervention with the next subject. Why using an across subjects design for this study? • It was easier to observe the effects of the intervention across subjects using this design. • Other designs (e.g., withdrawal design) would have been inappropriate. Once the requesting had increased, it is difficult to reverse this behavior in order to demonstrate a functional relationship. • Staggered introduction of the intervention helped build a strong case for verification and replication within the design itself. • Based on previous research conducted in the area of the milieu approach, it was expected before the study that there would be a functional relationship between the intervention and the subjects’ performance.

9. Limitations of the Study • It was difficult to get the mothers into the clinic for the intervention sessions. • The effects of the generalization with the mothers were not expected to be immediate due to the level of retardation of the students. • Suggestions: Future research should seek an extended study using control and experimental groups. • Although small groups are a strength of single subject research designs, such a small group (4 subjects) can affect degree of confidence in the generalizability of the intervention.

10. Multiple Baseline Across settings Design Cushing, L. S., & Kennedy, C. H. (1997). Academic effects of providing peer support in general education classrooms on students without disabilities. Journal of Applied Behavior Analysis, 30,139-151.

12. Table Continued

13. Across settings Design Why using an across settings design for this study? • Using across settings design was more convincing, than using only one setting, to demonstrate a functional relationship between independent and dependent variables. • The multiple baseline design offered the advantages of providing intervention in all settings of need without having to withdraw treatment.

14. Limitations of the Study • Because the sample of students was so selective, the robustness of the findings requires systematic replication across a variety of students without disabilities. • The question that hasn’t been answered is that whether positive effects would occur for students who are already performing at high levels in general education classes.

15. Issues with Multiple Baseline Designs • The time and resources are sometimes problematic. • There may be no other behaviors, settings, or individuals available who are in need of the intervention. • At times, the need to identify an effective intervention as quickly as possible is very important. In this case, alternating treatments design may be appropriate.