cross-sectional, case-control, and cohort studies.

1 In 2–3 paragraphs, in your own words, compare the following observational studies: cross-sectional, case-control, and cohort studies.
• Indicate the levels for which measures are being obtained in each type of study.
• Describe the purpose for which each study design is used.
• Explain a potential type of bias for each study design.
• Identify the measures of association for each type of study.
Describe accuracy, time commitment, and disadvantages for each type of study
2 In 2 –3 paragraphs, in your own words, compare controlled and quasi-experimental studies.
• For each type of study, describe the method for choosing participants.
• Describe the disadvantages and advantages to each type of study.
• Explain the ethical challenges for each type of study.
• Describe the strategies used to ensure validity within each type of study.
3 Find an observational study in the Walden Library on the disease you chose for PE4001. In 2–3 paragraphs, address the following about the study.
• Reference the research study in APA format.
• Identify the research question.
• Explain the study design that was used in the research study and justify the selection of this study design.
• Identify the participants.
• Identify the independent and dependent variables.
• There may be more than one variable, depending on the type of study.
• Explain how the independent and dependent variables are measured.
• Identify the selection criteria for cases and controls. (Indicate in the response if this is not applicable.)
• Explain the main results of the study.
• Explain the ethical issues involved in the study design.
• Identify the limitations noted by the authors that may represent potential bias.
• If the authors did not identify any limitations, identify one potential type of bias for the study.