1. SMALL-N DESIGNS What is a Small-N Design? What is a Reversal Design?
What is a Multiple Baselines Design?
How are Small-N Designs Analyzed?

2. What is a Small-N Design?
Experiment conducted on only one or a few subjects.
Available population may be small.
Internal validity is often very good - no individual differences.
External validity is a problem.

3. What is a Reversal Design?
Measure before treatment, with treatment, and after treatment is removed or reversed (ABA Design).
The treatment is the independent variable.
Measure the dependent variable at each stage of the design.

4. What is a Reversal Design?
Not appropriate for treatments with permanent effects
Variations:
ABAB
ABBA

5. What is a Multiple Baseline Design?
Compare before and with treatment; use other behaviors, situations, or subjects as baselines.
Useful when treatment has permanent effect.

6. Multiple Baseline: Behaviors
Behavior 1 before / Behavior 1 after Behavior 2 before ………. / Behavior 2 after Behavior 3 before ……………… TIME

7. Multiple Baseline: Situations
Situation 1 before / Situation 1 after Situation 2 before ………. / Situation 2 after Situation 3 before ……………… TIME

8. Multiple Baseline: Subjects
Subject 1 before / Subject 1 after Subject 2 before ………. / Subject 2 after Subject 3 before ……………… TIME

9. How Are Small-N Designs Analyzed?
Inferential statistics are not used.
Use descriptive statistics; graph data for each individual participant.