What must experiments must have
Independent Variable (I.V)
Dependent Variable (D.V)
Independent Variable
Variable that changes
Operationalised Independent Variable
Make measurable
Dependent Variable
Variable you measure
Extraneous Variable
Variables we need to control
Confounding variables
Factors other than the independent variable that may cause a result.
Examples of Participant Variables (3)
Any characteristic or aspect of a participant’s background
Examples of Situational Variables (3)
Environmental variables that alter participants’ behaviours
Standardised Procedure
Keeping everything the same. Control with sensible design
Counterbalancing
Random allocation
The process of assigning participants to different groups in a study using a random method to reduce bias.
Randomisation
A technique used in experiments to ensure every participant has an equal chance of being assigned to any group, enhancing the validity of the results.
Standardisation
The use of consistent procedures and conditions in a study to ensure that differences in outcomes are due to the variables being tested, not external factors.
Repeated measures design
Using the same participants in each condition. Two sets of materials matched for difficulty.
Strength of Repeated measures design (2)
Weakness of Repeated measures design (3)
Independent measures design
Using different participants in each condition.
Strength of Independent measures design (3)
Weakness of Independent measures design (2)
Matched pairs design
Using different but similar participants in each condition
Strength of Matched pairs design (2)
Weakness of Matched pairs design (3)
Lab experiment
Strength of Lab experiment