1. Describe the disadvantages of a multiple-treatment design, compared to a two-treatment design, for a within-subjects experiment. 2. Although the cohort effect can be a serious problem for...

1. Describe the disadvantages of a multiple-treatment design, compared to a two-treatment design, for a within-subjects experiment.

2. Although the cohort effect can be a serious problem for cross-sectional research, it is not a problem for longitudinal designs. Explain why not.