2.2.6 - operationalisation, extraneous variables and confounding variables

Question 1

what is operationalisation?

Answer 1

making the IV and DV precise and specific by deciding how the IV will be manipulated and how the DV will be recorded

Question 2

what does operationalisation allow?

Answer 2

for the study to be precisely replicated to check the conclusions are reliable

Question 3

what are operational definitions?

Answer 3

what the variables are and how you will measure them

Question 4

what can operational definitions of the dependent variable do?

Answer 4

increase objectivity in research, because the outcome is measured in the same way by all researchers and isn’t open to interpretation

Question 5

why is it important to control variables other than the independent and dependent variable in an experiment?

Answer 5

because if variables other than the IV differ between conditions in an experiment, researchers can’t conclude that the DV was really affected by the IV

Question 6

what are extraneous variables?

Answer 6

those which aren’t the IV, but may affect the DV

Question 7

what are confounding variables?

Answer 7

extraneous variables which affect conditions in a systematic way

Question 8

what are the two problems with confounding variables?

Answer 8

1. a difference found in the DV between two conditions may have been caused by the uncontrolled variable, so you conclude the IV has affected the DV when it hasn’t
2. the uncontrolled variable might cancel out the effects of the IV so you conclude the IV hasn’t affected the DV when actually it has