Research design that would call for repeated measures ANOVA.

Full Answer Section

Dependent Variable: Cardiovascular health, as measured by VO2 max (maximal oxygen consumption)

Repeated Measures ANOVA Design

To answer the research question using a repeated measures ANOVA design, the following steps would be taken:

1. Recruit a sample of older adults and randomly assign them to the aerobic exercise group or the resistance exercise group.
2. Measure the participants' VO2 max at baseline (before the start of the exercise program).
3. Have the participants complete the 12-week exercise program.
4. Measure the participants' VO2 max again at the end of the 12-week exercise program.

The data would then be analyzed using a repeated measures ANOVA to compare the changes in VO2 max between the two groups.

How the Research Question Could Have Been Answered Using a Between-Subjects Design

To answer the research question using a between-subjects design, the following steps would be taken:

1. Recruit two separate groups of older adults.
2. Randomly assign one group to the aerobic exercise program and the other group to the resistance exercise program.
3. Have the participants complete the 12-week exercise program.
4. Measure the participants' VO2 max at the end of the 12-week exercise program.

The data would then be analyzed using a t-test to compare the VO2 max of the two groups.

Advantages and Disadvantages of Repeated Measures ANOVA and Between-Subjects Designs

Repeated Measures ANOVA

Advantages:

• More powerful than between-subjects designs, because each participant serves as their own control.
• More efficient, because fewer participants are needed.

Disadvantages:

• Can be more difficult to implement, because participants must be measured multiple times.
• More susceptible to order effects and carryover effects.

Between-Subjects Designs

Advantages:

• Easier to implement than repeated measures ANOVA designs.
• Less susceptible to order effects and carryover effects.

Disadvantages:

• Less powerful than repeated measures ANOVA designs, because each participant does not serve as their own control.
• More participants are needed to achieve the same level of power.

Which Design to Use?

The best design to use depends on the specific research question and the resources available. If the research question is concerned with how a particular treatment affects individuals over time, then a repeated measures ANOVA design is the best choice. However, if the research question is concerned with comparing the effects of different treatments on different groups of people, then a between-subjects design is the best choice.

Conclusion

Repeated measures ANOVA is a powerful statistical tool that can be used to answer a variety of research questions. However, it is important to be aware of the potential advantages and disadvantages of this design before using it.

Sample Answer

Research Question: Does the type of exercise (aerobic vs. resistance) affect the improvement in cardiovascular health in older adults?

Independent Variable: Type of exercise (aerobic vs. resistance)

Levels of the Independent Variable:

• Aerobic exercise: 30 minutes of moderate-intensity aerobic exercise 3 times per week for 12 weeks.
• Resistance exercise: 2 sets of 10-12 repetitions of 8 different resistance exercises 2 times per week for 12 weeks.