Confounding Variable
Also called: confound, extraneous variable, threat to internal validity
Definition
An uncontrolled variable that changes along with the independent variable and could account for the observed effect. Common confounds in applied work include events outside the program, maturation, changes in measurement, and the intervention being delivered differently over time.
In plain language
Something else that changed at the same time as the treatment and might be the real reason the behavior changed.
Example
A student's disruptions fall the week the new plan starts, which is also the week a disruptive classmate moves away.
Not confounding variable
A variable the design holds constant across phases, such as the same observer recording in every condition.
See also
Written from
- kazdin-2011
Written from Kazdin (2011). No textbook glossary consulted.
This entry has not yet been through clinical review. Treat it as a draft.