The alternating treatments design compares the effects of two or more treatments on a behavior. It answers which treatment is more effective in changing a behavior. Treatments are alternated rapidly to evaluate their relative effects. There are three common variations: with no baseline, baseline followed by alternating treatments, and baseline followed by alternating treatments and a final treatment phase. It is used when determining the relative effectiveness of multiple treatments and baseline data is unavailable or unstable. Disadvantages include a lack of control for extraneous variables and an inability to assess absolute treatment effects.

1. Overview of Alternating
Treatments

2. Alternating Treatments Design
• Compares the effects of two or more
treatments on the same behavior.
• Answers the question “Is one treatment more
effective than another?”
• The purpose is to determine which condition
is more effective in changing one behavior.
• Basic concept: When two or more treatments
are alternated rapidly in time, you can
evaluate the relative effects of the treatments.

3. Alternating Treatments Design
• Alternating treatments with no baseline
– Treatments are presented randomly to the subjects across
different days, across times of day, or within sessions
– Pre-intervention baseline data are not collected.
• Baseline followed by alternating treatments
– Baseline data are collected before the presentation of the
treatments and provide additional information about changes
from pre-treatment to treatment
• Baseline followed by alternating treatments and a final treatment
phase
– Ends in a final treatment phase that has been determined to be
the most effective during the study

4. Examples of Alternating Treatments

5. Examples of Alternating Treatments

6. Alternating Treatments Design
• Use when:
– You want to determine the relative effectiveness
of more than one treatment on a given behavior
– Baseline data are either unavailable or might be
unstable
– Treatments are sufficiently different from each
other
– Participants can discriminate the treatment
conditions

7. Alternating Treatments Design
• Disadvantages
– No controls for extraneous variables are present.
You cannot make statements about absolute
effects of treatment, only relative ones
– Not an appropriate design for behavior that is
learned in stages.
– Should not be used when treatments need to be
administered continuously to be effective