Tag Archives: Lurking variables

Learning from bad experiments

Thinking about bad experiments is a good device helping reinforce the concepts of experimental design. No one should deliberately perform an experiment with a defective design. However, thinking about such designs is a great learning device. For example, why does … Continue reading

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Thinking about study designs

When learning the designs of research studies, an effective exercise is to look at examples drawn from actual research studies. In this post, we present a series of eight research studies. For each study, the exercise is to classify each … Continue reading

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Design of Observational Studies

There are numerous ways to collect data when conducting research. The study design depends greatly on the nature of the research question. There are two key areas of statistics that provide ways of collecting data, namely the idea of sampling … Continue reading

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Design of experiments

When the goal in a statistical study is to understand cause and effect, experiments are the only way to obtain convincing evidence for causation. This is an introductory discussion on experimental design, introducing its vocabulary, its characteristics and its principles. … Continue reading

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A Landmark Lipitor Study of Patients with Type 2 Diabetes

People with diabetes are at high risk for heart disease and stroke. Since elevated lipid levels are associated with cardiovascular vascular disease, keeping blood cholesterol close to the recommended target numbers can lower the risk. The American Diabetes Association has … Continue reading

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What science learned from a group of elderly nuns

The Nun Study is a longitudinal study of aging and Alzheimer’s disease. It followed 678 sisters of the School Sisters of Notre Dame living in Mankato, Minnesota. The goal of the study is to identify the risk factors for Alzheimer’s … Continue reading

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