What is internal validity?
Extent to which the experiment shows the changes in the behavior are due to the independent variable and not the result of uncontrolled or confounding variables
Examples of confounding variables:
-Starting medication
-Change in home life (divorce, death, new baby, move, etc)
-Change in school/therapy life (new therapists, clinicians, new building, new school, etc.)
What is external validity?
The degree to which a study's findings have generality to other subjects, settings, and/or behaviors
-Will this study prove effective if a different population of participants is used?
-Will this study be effective if used with a different type of behaviors?
If the study was done in a clinic, will it be effective if conducted in a school classroom setting? What about in a home environment?
Resources: Cooper J.O, Heron T.E, Heward W.L. Applied behavior analysis (2nd ed.) Upper Saddle River, NJ: Pearson; 2007.
