Question

A researcher introduces a second factor due to individual differences to create a factorial design from an independent-measures design. Why can this help the researcher draw conclusions about the data set?

a. It can reduce the variability within the treatment groups.

b. It can increase the variability within the treatment groups.

c. It creates larger sample sizes.

d. It creates smaller sample sizes.

Answer 1

Ans:

Correct option is a:

It can reduce the variability within the treatment groups.

In the case of reducing variability, the researcher may find that results are non-significant in one study,and find that when particpants are divided into groups based on a characteristic suh as age or ethnicity the results are more clear.

The procedure is the same as 'adding a second factor' and the rationale for doing it is different, in the first case it is to get a better understanding of how the original independent variable operates under different condtions, in the second it is to reduce variability of particpant groups so that it is more likely that if there is a significant difference - it will be detected.