An extraneous variable that influences both the independent and dependent variables, potentially biasing results
Involves independent variable manipulation and aims for causality, but lacks random assignment or counterbalancing
The same participants are tested across all conditions or treatments
A method used in experimental studies to deal with confounding variables by distributing participants into groups by chance
Participants are tested in a single condition, with different groups for each condition
Aims to show causal relationships by manipulating an independent variable with random assignment
Studies relationships between variables without manipulation, thus not establishing causality
