Chapters 9 & 10 (Richards text) Chapter 8 (Cooper text) – Alternating Treatments Designs in Single-Subject Research

1. Chapters 9 & 10 (Richards text)Chapter 8 (Cooper text) – Alternating TreatmentsDesigns in Single-Subject Research Ps534 Dr. Ken Reeve Caldwell College Graduate Programs in ABA

2. Review: Single-Case Experimental Designs Issues For each design we will ask the following: • Does the design allow us to see a change in DV (without regard to whether it was caused by the IV)? • Does the design allow us to infer a functional relationship between IV and DV? Why does it allows this? • What threats to internal validity (confounds) does the design control for? • What ethical issues are important to know about using a particular design?

3. Purpose: Alternating Treatments Designs Main Purpose: We examine the effects of TWO (or more) DIFFERENT IVs (treatments) on a SINGLE DV (target behavior) • Can be done with a baseline • Can be done without a baseline • Can also end on a single treatment • Also called MULTI-ELEMENT DESIN • Also called MULTIPLE-SCHEDULE DESIGN

5. How To Do Alt Treatment Designs • Begin with single participant (each participant is a SEPARATE experiment and serves as his or her own control like in a withdrawal design) • Take baseline IF POSSIBLE (not necessary to demonstrate experimental control but desirable) • When you implement TREATMENTS, you “rapidly” alternate between them from one session to the next • Useful to have “cue” or discriminative stimulus to signal to child what condition is in effect • You can either COUNTERBALANCE or randomly present the conditions (this is done so that we reduce possible confound of order/sequence effects)

6. Types of AT Designs: No Baseline Type Notice that “no treatment” phase (A) takes place of a regular BL

7. Issues About No Baseline Type of AT Designs: • Issues: We can clearly determine which treatment is MORE effective than other treatment(s) • And…we can clearly determine which treatment is MORE effective than NO treatment phase • So…this means we DO have a functional relationship and we DO have good internal validity • BUT…

8. Issues About No Baseline Type of AT Designs: • BUT…we do not know whether the picture we get of the “no treatment” phase is what it would look like if we had a “regular” baseline • A small point, perhaps, but design is slightly stronger if you have a baseline • Ethical issues may preclude a regular baseline, though!

9. Types of AT Designs: With Baseline Type

10. Types of AT Designs: End on Single Treatment Type You end with the better treatment!

11. General Advantages AT Designs • Avoids withdrawal of treatment found in an ABAB reversal design • Avoids ethical problems of long “no treatment” baselines (if you do the AT with no baseline design) • Allows us to determine more (most) effective treatment very economically

12. General Disadvantages AT Designs • May be unable to do AT design if treatments have carry-over effects (so need to determine if this is a problem) • Can’t do this if learning (change in behavior) is permanent since this would result in no reversibility of data • May be difficult to do AT if student/client is not skilled in discrimination among conditions!

13. Design a study using AT Design • Question: You wish to compare the effects of two different reinforcement procedures on a child’s academic task completion • How would you do it?

14. End