Studies relationships between variables without manipulation, thus not establishing causality

Participants are tested in a single condition, with different groups for each condition

A method used in experimental studies to deal with confounding variables by distributing participants into groups by chance

Aims to show causal relationships by manipulating an independent variable with random assignment

An extraneous variable that influences both the independent and dependent variables, potentially biasing results

The same participants are tested across all conditions or treatments

Involves independent variable manipulation and aims for causality, but lacks random assignment or counterbalancing