Tag Archives: number of samples

Polls Apart

Election season is fast approaching so you can be sure a plethora of polls will soon be adding to the mayhem. Polls educate us in two ways. They tell us what we, or at least the population being polled, think. … Continue reading

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Regression Fantasies: Part III

Is Your Regression Model Telling the Truth? There are many technologies we use in our lives without really understanding how they work. Television. Computers. Cell phones. Microwave ovens. Cars. Even many things about the human body are not well understood. … Continue reading

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Regression Fantasies: Part I

Five Common Reasons for Doubting a Regression Model Finding a model that fits a set of data is one of the most common goals in data analysis. Least squares regression is the most commonly used tool for achieving this goal. … Continue reading

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Six Misconceptions about Statistics You May Get From Stats 101

When you learn new things, you can develop misconceptions. Maybe it’s the result of something you didn’t understand correctly. Maybe it’s the way the instructor explains something. Or maybe, it’s something unspoken, something you assume or infer from what was … Continue reading

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Limits of Confusion

A confidence interval is the numerical interval around the mean of a sample from a population that has a certain confidence of including the mean of the entire population. “Say what?” OK, let’s take it one point at a time. … Continue reading

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A Picture Worth 140,000 Words

Even if it’s been a while since your last statistics class, when you read Stats with Cats: The Domesticated Guide to Statistics, Models, Graphs, and Other Breeds of Data Analysis you’ll figure out that there’s much more to data analysis … Continue reading

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Grasping at Flaws

Even if you’re not a statistician, you may one day find yourself in the position of reviewing a statistical analysis that was done by someone else. It may be an associate, someone who works for you, or even a competitor. … Continue reading

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Secrets of Good Correlations

If you’ve ever seen a correlation coefficient, you’ve probably looked at the number and wondered, is that good? Is a correlation of -0.73 good but not a correlation of +0.58? Just what is a good correlation and what makes a … Continue reading

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Ten Fatal Flaws in Data Analysis

1. Where’s the Beef? In a way, the worst flaw a data analysis can have is no analysis at all. Instead, you get data lists, sorts and queries, and maybe some simple descriptive statistics but nothing that addresses objectives, answers … Continue reading

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It was Professor Plot in the Diagram with a Graph

You probably were taught how to graph data in high school. Depending on your work, you may frequently plot data yourself or look at graphs prepared by others. Even if you don’t use graphs on your job, you may run … Continue reading

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