Tag Archives: Observational studies

Is your public pool free from urine?

Some people believe that the answer to the question posted in the title of the blog post is no. Now there is evidence to back it up. The study profiled here also gives an indication of how serious the problem … Continue reading

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Is there anything we can do to avoid the flu?

In many places, influenza activity peaks during the period in between December and February. What are some of the best practices to reduce the spread of the flu and to minimize the risk of catching it? The standard recommendations are: … Continue reading

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Is College Worth It?

Is college worth it? This was the question posed by the authors of the report called College Majors, Unemployment and Earnings, which was produced recently by The Center on Education and the Workforce. We do not plan on giving an … Continue reading

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Presidential Elections and Statistical Inference

We use an example of presidential elections to illustrate the reasoning process of statistical inference. The current holder of a political office is called an incumbent. Does being an incumbent give an edge for reelection? The answer seems to be … Continue reading

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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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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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