IB Psychology 1.2.2 Establishing Cause-effect Relationships Key Definitions

A relationship in which a change in the independent variable directly produces a change in the dependent variable.

A research design that compares groups on a pre-existing variable the researcher cannot manipulate or randomly assign.

Sorting participants into experimental conditions by chance, so each participant has an equal probability of being in any condition.

A research design that manipulates the independent variable, randomly assigns participants to conditions, and controls confounding variables.