Control of variables

Question 1

Define the key term ‘Extraneous Variable’.

Answer 1

Any variables besides IV that may have an effect on the DV if it’s not controlled.
EV’s don’t vary systematically with the IV.

Question 2

Define the key term ‘Confounding Variable’.

Answer 2

Any variable besides the IV that may have affected the DV so we’re unsure of the true source of changes to the DV.
CV’s vary systematically with the IV.

Question 3

Define the key term ‘Demand Characteristic’.

Answer 3

Any cue from the researcher or experimental situation that reveals the purpose of the study to participants.
This can lead to PPs changing their behaviour in the experiment.

Question 4

Define the key term ‘Investigator Effect’.

Answer 4

Any conscious or unconscious effect of the researcher on the research outcome (DV).

Question 5

Give examples of investigator effects.

Answer 5

Design of the study.
Selection of participants.
Interaction with participants.

Question 6

Define the key term ‘Randomisation’.

Answer 6

The use of chance to control bias when designing the experiment and order of conditions.

Question 7

Define the key term ‘Standardisation’.

Answer 7

Using the same formalised procedures for every participant