1. Calculating Effect Sizes for Single Subject Designs
8.1
Calculating Effect Sizes for Single Subject Designs

2. Classes of Effect Size Formulae
Percentage of Non-Overlapping Data (PND)
Identify the lowest baseline point
Count the number of non-overlapping intervention points
Calculate the proportion of non-overlapping to total number of intervention points (can’t use if baseline has a zero point)

3. PND = 8/10 = 80%

4. Classes of Effect Size Formulae
Standard Mean Difference
Subtract the mean of the baseline phase from the mean of the intervention phase
Divided by standard deviation of baseline

5. SMDall= 7.23
SMD3= 8.25

6. Classes of Effect Size Formulae
Percentage Reduction (mean baseline reduction)
Subtract the average of last 3 Tx points from the average of the last 3 baseline points
Divide by the average of the last 3 baseline points
Multiply by 100 for percent of baseline reduction

7. MBR=339.00

8. Classes of Effect Size Formulae
Regression Models
Regression equation obtained for baseline
Regression equation obtained for Tx data
Tx substracted from baseline and divided by standard deviation of baseline

9. Olive & Smith, 2005