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What is Degrees of Freedom?

May 27th, 2020 by

No, degrees of freedom is not “having one foot out the door”!

Definitions are rarely very good at explaining the meaning of something. At least not in statistics. Degrees of freedom: “the number of independent values or quantities which can be assigned to a statistical distribution”.

This is no exception.

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Member Training: Seven Fundamental Tests for Categorical Data

May 1st, 2020 by

In the world of statistical analyses, there are many tests and methods that for categorical data. Many become extremely complex, especially as the number of variables increases. But sometimes we need an analysis for only one or two categorical variables at a time. When that is the case, one of these seven fundamental tests may come in handy.

These tests apply to nominal data (categories with no order to them) and a few can apply to other types of data as well. They allow us to test for goodness of fit, independence, or homogeneity—and yes, we will discuss the difference! Whether these tests are new to you, or you need a good refresher, this training will help you understand how they work and when each is appropriate to use.

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Member Training: Practical Suggestions for Improving Your Scatterplots

April 1st, 2020 by

The scatterplot is a simple display of the relationship between two, or sometimes three, variables. You have a wide range of options for displaying a scatterplot. In particular, you can control the location, size, shape, and color of the points in your scatterplot.

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The Right Analysis or the Best Analysis? What to Do When You Can’t Run the Ideal Analysis 

March 9th, 2020 by

One activity in data analysis that can seem impossible is the quest to find the right analysis. I applaud the conscientiousness and integrity that underlies this quest.

The problem: in many data situations there isn’t one right analysis.

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Member Training: Confusing Statistical Terms

February 28th, 2020 by

Learning statistics is difficult enough; throw in some especially confusing terminology and it can feel impossible! There are many ways that statistical language can be confusing.

Some terms mean one thing in the English language, but have another (usually more specific) meaning in statistics.  (more…)


Should Confidence Intervals or Tests of Significance be Used?

December 20th, 2019 by

What is a Confidence Interval?

Any sample-based findings used to generalize a population are subject to sampling error. In other words, sample statistics won’t exactly match the population parameters they estimate.

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