1. Simultaneous / Alternating Treatment Designs

2. Also known as: Multi-element baseline design Multiple schedule design
Concurrent schedule design

3. Overview Efficient for comparing effects of 2 or more treatments
Alternated in a variety of ways
A distinct stimulus is often associated with each treatment
Involves prediction, verification, and replication

4. Logic of Simultaneous or Alternating Treatments Design
Experimental control is demonstrated with different levels of response in different treatments
Allows for quick comparison
Stresses importance of evaluating individualized treatments

5. Design Variations Single phase without no-treatment control condition
Single phase with one no-treatment control condition
Two phase with initial baseline
Three phase with baseline and final best treatment phase

6. Without No-Treatment Control Condition

7. With No-Treatment Control Condition

8. With Baseline and Final Best Treatment Phase

9. Design Advantages Does not require treatment withdrawal
Speed of comparison
Minimizes irreversibility problem
Minimizes sequence effects
Can be used with unstable data
Can be used to assess generalization of effects
Intervention can begin immediately

10. Design Disadvantages Multiple treatment interference
Unnatural nature of rapidly alternating treatments
Limited capacity (max. of 4 conditions)
Selection of treatments – should be significantly different from one another

11. Conclusions Good way to examine a lot of options
Need to be careful to not do too many
Client may become overwhelmed
Client may become confused about what to do
You may lose track of what you are doing.