Experimental control is the degree to which the same intervention can be shown to have a predictable effect on behavior. The point of experimental control is to demonstrate a functional relationship between a behavior (dependent variable) and intervention (independent variable). 

In applied behavior analysis, (ABA) behaviorists are constantly validating that interventions work by analysis and experimentation. If a behavior change only occurs once, it is very difficult to determine a functional relationship or causation. Repeatability or replication is what best demonstrates experimental control. 

Internal Validity 

Internal validity is the extent to which the researcher can show that the behavior change that occurred during an intervention was a direct result of the manipulation of the independent variable. Simple put, was the treatment the cause for the behavior change. 

Confounding Variables (Extraneous Factors)

Confounding variables are anything that occur outside of the treatment that could affect the experiment. The goal of any experiment is to limit these factors but they can never be completely avoided. Some examples of things that could affect an experiment are: 

  • The air conditioner is broken.
  • A child has a tantrum at home prior to an intervention taking place.
  • A child is not feeling well.
  • A child did not get a lot of sleep that night.
  • There is noise outside of the intervention room.

As you can see, these are all factors that are not part of the experiment. You want to limit these factors to whatever degree possible to ensure the study has internal validity. 

This article is useful for registered behavior technicians (RBT) or students who are studying to become board certified behavior analysts (BCBAs). Understanding (Applied Behavior Analysis) ABA terms is critical for both being an effective ABA therapist and passing your BCBA exam


In an effort to help you study for your BCBA exam more effectively, this post is written in a “study note” form rather than as a long form blog post. 

They are my personal study notes I am sharing with you as a gift. I am spending my time studying so they are not edited. I am grateful for your understanding in overlooking the grammar! Happy Studying! 


Cooper, J. O., Heron, T. E., & Heward, W. L. (2007). Applied Behavior Analysis (3rd Edition). Hoboken, NJ: Pearson Education.

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