Measurements compared to see if they are associated
Independent Variables
Manipulated conditions of the experiment
Dependent Variables
Measured change in the condition
Extraneous Variables
Any variable (except IV) that can influence measurement of the DV
Demand Characteristics
Discovering the aim, altering behaviour to suit what they think is wanted in the study
Participant Variables
Relevant characteristics, knowledge or skills related to the task
Situational Variables
Environmental factors present in the condition
Order Effect
Alter performance of the conditions
Confounding Variables
Changes systematically between levels of IV
Controlling Extraneous Variables:
Random allocation
Randomisation of IV
Matched pairs
Counterbalancing
Standardisation
Single/Double blind trials
Pilot Studies
Small scale of main study to improve quality and control
Peer Review
Experts reading over study, pointing out any confounding variables that could be present, but would then lack internal validity and need to be repeated
