variables Flashcards
What is an independent variable (IV)?
The variable that is manipulated or changed by the researcher to observe its effect on the dependent variable.
What is a dependent variable (DV)?
The variable that is measured by the researcher. It is expected to change as a result of the IV.
What is an operationalised variable?
A variable that is clearly defined and stated in a way that makes it measurable and testable.
E.g., “memory” operationalised as “number of words recalled from a list of 20”.
Why is operationalisation important?
✔ Increases validity and replicability.
✔ Makes it clear what is being measured or manipulated.
✔ Ensures other researchers can repeat the study accurately.
What are extraneous variables?
Variables other than the IV that could affect the DV if not controlled.
They reduce internal validity if they influence the outcome.
What are confounding variables?
A type of extraneous variable that has actually affected the DV and therefore confounds the results.
Makes it unclear whether the IV caused the change in the DV.
What is a situational variable?
An extraneous variable related to the environment (e.g., noise, temperature, time of day) that could affect the DV.
What is a participant variable?
An extraneous variable related to individual differences (e.g., age, IQ, personality) that may affect the DV.
What is a control variable?
A variable that is kept constant to prevent it affecting the DV.
Helps to ensure validity of the results.
What are demand characteristics?
Cues in an experiment that may lead participants to guess the aim and change their behaviour, reducing validity.
What is investigator effect (experimenter bias)?
When the researcher’s behaviour or expectations influence participants’ responses, potentially affecting the DV.
What is random allocation and why is it used?
Participants are randomly assigned to conditions to reduce the impact of participant variables and ensure groups are equivalent.
How can extraneous and confounding variables be controlled?
✔ Standardised procedures.
✔ Random allocation (controls participant variables).
✔ Counterbalancing (in repeated measures).
✔ Use of control groups.
What is standardisation in experiments?
Keeping all procedures identical for all participants to minimise extraneous variables and allow replication.
