Question

Below is a description of a fictitious study. Read the description and then answer the factual questions that follow:

            Brusser and Janosy (20xx) wanted to test the effectiveness of a new relaxation/biofeedback intervention on menopausal symptoms. They invited women who presented themselves in an outpatient clinic with complaints of severe hot flashes to participate in the study of the experimental treatment. These 30 women were asked to record, every day for 2 weeks before their treatment, the frequency and duration of their hot flashes. The intervention involved five 1-hour sessions over a period of a week. Then, for the 2 weeks after the treatment, the women were asked to record their hot flashes again every day. At the end of the study, Brusser and Janosy found that, on average, both the frequency and average duration of the hot flashes had been significantly reduced in their sample of 30 women. They concluded that their intervention was an effective alternative to estrogen replacement therapy in treating menopausal hot flashes.

1. What is the independent variable in this study?
   
2. What is the dependent variable in this study?
   
3. Was random assignment used in this study?
   
4. Is the design experimental, quasi-experimental, or nonexperimental?
   
5. What is the specific name of the design used in this study?
   
6. Was blinding used in this study?
   
7. Was selection a possible threat to the internal validity of this study?
   
8. Was history a possible threat to the internal validity of this study?
   
9. Was mortality a possible threat to the internal validity of the study?
   
10. Discuss ways in which this study achieved or failed to achieve the criteria for making causal inferences.
    
11. Propose a more powerful research design to address the same research question. Describe various components of the design in detail.
    

Answer 1

What is the independent variable in this study?

The independent variable is the variable that changes the dependent variable. The independent variable in this study is exposure Vs non-exposure to relaxation/ biofeedback intervention.

What is the dependent variable in this study?

The dependent variable is the variable that is being measured, observed, tested in an research study. The dependent variable in this study is hot flashes.

Was random assignment used in this study?

No. Random assignment was not used in this study. The participants were selected based on menopausal symptoms.

Is the design experimental, quasi-experimental, or nonexperimental?

A quasi-experimental design was used in this study. Because the independent variable of exposure Vs non-exposure participants was selected based on the menopausal symptoms and not based on random selection.

What is the specific name of the design used in this study?

Time series was the specific design used in this study. The participants were observed for every day for about two weeks before and after the treatment.

Was blinding used in this study?

No. The participants were fully aware of the intervention and treatment used in the research study. The researcher also knows about women exposed to Specific treatment.

Was selection a possible threat to the internal validity of this study?

Here the cause and effect relationship was not studied. The women were compared themselves before and after the treatment. So there is no possible threat to internal validity.

Was history a possible threat to the internal validity of this study?

Yes. It is possible that women exposed to estrogen replacement during the course of study may be cause for reduced hot flashes.

Was mortality a possible threat to the internal validity of the study?

No. The participants remain the same throughout the five weeks of study. So mortality was not a possible threat to the internal validity of the study.