Overview of Alternating Treatments

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.

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

Examples of Alternating Treatments

Examples of Alternating Treatments

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

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