3.2.2 confounding variables

Question 1

why could it be said there are other variables besides the independent variable that can have an impact on the dependent variable in an experiement

Answer 1

due to the complexities of biological systems

Question 2

what is a confounding variable

Answer 2

a variable besides the independent variable that has an effect on the dependent variable in a reaction

Question 3

what can be done to minimise the impact of confounding variables

Answer 3

they should be held constant if possible, or at least monitored so their effect on the results can be accounted for in the analysis

Question 4

what can be used if it is not possible to control a confounding variable

Answer 4

a randomised block design

Question 5

what is a randomised block design

Answer 5

these are used alongside control groups and can be distributed in such a way that the influence of any confounding variable is not likely to be the same across the treatment and control groups