Which variables are those that a researcher chooses to study in order to assess their possible effects on one or more other variables?

Independent variables are those a researcher chooses to study for their possible effects on other variables.

They act as the presumed causes whose influence is examined.

Dependent variables are the outcomes affected, not the ones chosen to exert an effect.

Extraneous variables are unwanted influences the researcher tries to control, not the focus of study.

Confounding variables blur the cause and effect link rather than being deliberately studied causes.

In experiments the independent variable is the one the researcher actively manipulates.