What is the experimental method?
A method that examines cause and effect by changing or comparing an IV and measuring a DV.
What is an aim?
A general statement of what the researcher intends to investigate.
What is a hypothesis?
A clear, precise and testable prediction about a difference or relationship between variables.
What is the difference between directional and non-directional hypotheses?
A directional hypothesis predicts which way an effect will go. A non-directional hypothesis predicts a difference or relationship but not its direction.
What is an independent variable?
The variable manipulated by the researcher or used to define the conditions being compared.
What is a dependent variable?
The outcome that is measured to assess the effect of the IV.
What does operationalisation mean?
Defining a variable using the exact procedure used to manipulate or measure it.
Why control extraneous variables?
To reduce alternative explanations for changes in the DV and increase internal validity.
How do laboratory and field experiments differ?
Both involve manipulation of the IV, but laboratory experiments use controlled settings while field experiments take place in natural settings.
How do natural and quasi-experiments differ?
In a natural experiment the IV occurs naturally; in a quasi-experiment the IV is a pre-existing participant difference, such as age or diagnosis.