Question

a) Why are repeated measures designs more powerful than between subjects designs? Mention the error term.

b) If you were to compute a repeated measures ANOVA as a between subjects ANOVA how would the results differ?

Answer 1

1) Repeated measure designs have more power and thus, it works even if we use less number of subjects in our design. As the number of subject are less, our time and money over the design is saved.

Error = Within group variability - variability due to subjects

2) In a between subjects design, each subject receives only one treatment (not like within subject design. so, each subject here will not receive multiple treatments.

In a between subjects ANOVA, the total variance is comprised of treatment variance and error variance.the differences between groups are checked by examining . The error variance in this design can be comes from individual differences between subjects (e.g., demographic differences). i.e., The “noise” of the variance due to individual differences teslls us what impact our treatment is having.

And thus, we will not be able to divide up the variance. (Partition the variance due to individual treatment differencing from error variance)