control of variables

Question 1

extraneous variables

Answer 1

any other variable which is not the IV that affects the DV and does not vary systematically with the IV

eg lighting or age

Question 2

confounding variables

Answer 2

a variable other than the IV which has an effect on the DV - do change systematically with the IV

eg time of day a sleep study occurs

Question 3

demand characteristics

Answer 3

any cue the researcher or the research situation may give which makes the participants feel like they can guess the aim of the investigation

Question 4

investigator effects

Answer 4

any unwanted influence from the researcher’s behaviour, either conscious or unconscious, on the DV measured

eg design of study