Factorial designs allow researchers to study the effects of more than one independent variable simultaneously. Why is this advantageous? What information can factorial designs yield that nonfactorial designs cannot?

Question

What will be an ideal response?

Answer 1

This is advantageous because researchers are often interested in more than one effect on the dependent variable. Oceanographers may want to study effects related to both water temperature and salinity. Child welfare workers may want to study the effects of family income, mother's education level, and history of abuse on coping ability. The factorial design not only allows researchers to study these various factors independently, but their interactions can be studied as well. Studying interactions allows researchers to investigate the extent to which two or more factors influence each other. Perhaps whales encounter health problems in warmer water only at certain levels of salinity. Perhaps parents cope more successfully with stress when both family income and/or education level surpass a certain threshold. Or perhaps family income influences coping ability only when there is no history of abuse.