Control of variables

Question 1

Independent Variable

Answer 1

The variable that is changed/manipulated by the researcher (cause)

Question 2

Dependent Variable

Answer 2

The variable which is measured by the researcher (effect)

Question 3

Extraneous Variable

Answer 3

Any variable, other than the IV, that may have an effect on the DV if it is not controlled.

Essentially ‘nuisance variables’ that do not vary systematically with the IV

Question 4

Confounding Variable

Answer 4

Any variable, other than the IV, that may have affected the DV so we cannot be sure of the true source of changes to the DV.

Confounding variables vary systematically with the IV

Question 5

Demand Characteristics

Answer 5

Any cue from the researcher/situation that may be interpreted by PPs as revealing the purpose of the investigation

May lead to PPs changing their behaviour within the research investigation

Question 6

Investigator Effects

Answer 6

Any effect of the investigator’s behaviour (conscious/unconscious) on the research outcome (DV)

Question 7

Randomisation

Answer 7

The use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions.
- Largely to control investigator effects

Question 8

Random allocation

Answer 8

Can also be used where if PPs only take part in one condition then they are assigned to the condition they will take part in
- Can help to control participant variables

Question 9

Standardisation

Answer 9

Using the exact same formalised procedures and instructions for all participants in a research study
- Helps to control situational extraneous variables

Question 10

Counterbalancing

Answer 10

An attempt to control for order effects when participants take part in more than one condition. Counterbalancing involves half the participants taking part in condition A then B, and the others vice versa.

Avoids boredom or practice, impacting results positively

Question 11

Single-blind procedures

Answer 11

Where the participant is not told the aim of the research or any other detail. This is an attempt to control for the confounding effects of demand characteristics

Question 12

Double-blind procedures

Answer 12

Where neither the participant nor the researcher who conducts the study is aware of the aims. Often used to minimise the confounding effects of both demand characteristics and investigator effects