experiments - extraneous and confounding variables

Question 1

extraneous variable definition

Answer 1

• unwanted/extra variable other than IV
• could have effect on DV
• lowers internal validity

Question 2

3 main causes of extraneous variables

Answer 2

1. situational factors e.g.standardised instructions/task difficulty
2. participant variables e.g. age/gender/IQ
3. experimenter variables e.g. investigator effects

Question 3

confounding variable definition

Answer 3

• extraneous variable not controlled
• DOES have effect on DV

Question 4

difference between confounding and extraneous variables

Answer 4

extraneous variable = COULD have effect on DV
confounding variable = DOES have effect on DV