Alternating Treatment Design

Advantages

• Effective Determination: Quickly determines the most effective intervention among several.
• No Baseline Required: Baseline data is not needed or does not need to be stable before intervention.
• No Withdrawal Required: Does not require withdrawal of treatment.
• Efficiency: Reduces time administering ineffective treatments.
• Counterbalancing: Helps eliminate sequencing effects by alternating and randomizing intervention order.

When to Use

• Comparing Effectiveness: To determine relative effectiveness of more than one treatment on a behavior.
• Unstable or Unavailable Baseline: When baseline data is unavailable or unstable.
• Distinct Treatments: Treatments must be sufficiently different for subjects to distinguish.
• Sequencing Effects: When sequencing effects might obscure results.

Disadvantages

• Multiple Treatment Interference: Rapid alternation may cause interference affecting results.
  • Minimization: Use distinctly different treatments and present most effective treatment last.
• Irreversible Behaviors: Not suitable for non-reversible target behaviors.
• Slow Change Interventions: Ineffective for slowly changing or continuously needed interventions.
• Artificial Implementation: Rapid alternation may seem artificial outside a natural environment.
• Complex Counterbalancing: Difficult to counterbalance more than three treatments; excessive treatments can confuse participants.
• Subject Discrimination: Not suitable for subjects unable to discriminate between treatment conditions.

When Not to Use

• Interfering Treatments: When treatments interact and obscure results.
• Indistinguishable Treatments: When subjects cannot discriminate between conditions.
• Continuous Treatments: When treatments require continuous administration.
• Complex Counterbalancing: Difficulties in counterbalancing treatments.

Adaptations of Alternating Treatment Design

• Multi-Element Design: Evaluates factors influencing behavior for effective intervention development.
  • Used in functional behavioral assessments.
• Simultaneous Treatment Design: Concurrent treatments instead of alternated; rare in literature.
  • Approximates natural conditions better.
  • Requires more skill and planning.
• Adapted Alternating Treatment Design: Applies interventions to different behaviors of equal difficulty but independent.
  • Time-consuming but necessary for effectiveness.

Example from Textbook

• Study with Leticia: Fourth grader increased correct spelling using a computer program and peer tutoring.
  • Baseline data collected with stable baseline observed.
  • Rapid alternation between computer instruction and peer tutoring.
  • Computer instruction showed a positive increasing trend compared to peer tutoring.
  • Final treatment phase validated the effectiveness of computer instruction.

Conclusion

• Despite complexities, alternating treatment design is effective for evaluating multiple interventions.
• Works best with reversible behaviors and conditions allowing counterbalancing and data collection.
• Remains a practical choice for researchers and educators.