Control of variables

Question 1

Extraneous variable

Answer 1

any variable, other than the independent variable, that may have an effect on the dependent variable if it is not controlled.
Do not vary systematically with the IV

Question 2

Confounding variables

Answer 2

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 3

Demand characteristics

Answer 3

any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of the investigation.
This may lead to a participant changing their behaviour within the research situation

Question 4

Investigator effects

Answer 4

any effect of the investigator’s behaviour (conscious or unconscious) on the research outcome (the DV). This may include everything from the design of the study to the study to the selection of, and interaction with, participants during the research process

Question 5

Randomisation

Answer 5

the use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions

Question 6

Standardisation

Answer 6

using exactly the same formalised procedures and instructions for all participants in a research study