Garaci et al. (2012) examined a sample of people with and without multiple scler
ID: 3273486 • Letter: G
Question
Garaci et al. (2012) examined a sample of people with and without multiple sclerosis (MS) to test the controversial idea that the disease is caused by blood flow restriction resulting from a vein condition known as chronic cerebrospinal venous insufficiency (CCSVI). Of 39 randomly sampled patients with MS, 25 were found to have CCSVI and 14 were not. Of 26 healthy control subjects, 14 were found to have CCSVI and 12 were not. The researchers found an asso- ciation between CCSVI and MS. a. What is the explanatory variable and what is the response variable? b. Is this an experimental study or an observational study?
Explanation / Answer
a) Here we are trying to find if MS is caused by CCSVI,
Therefore CCSVI is the independent variable here and MS is the dependent variable
b) This is an observational study as it draws inferences from a sample to a population where the independent variable is not under the control of the researcher because of ethical concerns or logistical constraints.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.