Internal Validity

Definition

Internal validity refers to how well an experiment is done, especially whether it avoids confounding (more than one possible independent variable [cause] acting at the same time).

Related terms

Control Group:

A group in an experiment that does not receive treatment by researchers and is then used as a benchmark to measure how the other tested subjects do.

Random Assignment:

An experimental technique for assigning human participants or animal subjects to different groups in an experiment using randomization.

Confounding Variable:

An outside influence that changes the effect of a dependent and independent variable. This extraneous influence is used to influence the outcome of an experimental design intentionally.