Author Archives: StatsProf

Understanding Logistic Regression Output:
Part 1 — The Coefficient Table

As with least-squares linear regression, the most important part of the output of a logistic regression is the regression coefficient table. In this five-part series of articles, which parallels and references the five-part series reviewing the least-squares regression coefficient table, … Continue reading

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What is Ordinal Logistic Regression?

Ordinal Logistic Regression is logistic regression using an ordinal variable. An ordinal variable is a categorical variable where order matters. A variable that takes on the values of “very bad,” “bad,” “mediocre,” “good,” “very good” would be an example. The … Continue reading

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What is Nominal Logistic Regression?

Nominal Logistic Regression is logistic regression using a nominal variable as the dependent Y variable. The “nom” in “nominal’ comes from the Latin for “name” (not “number”) like in the word “nomenclature.” So a nominal variable is a variable whose … Continue reading

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Least-Squares Background Part 5 — Assessing Uncertainty

In this Article, I discuss assessing the uncertainty of the regression coefficient estimates and will briefly touch on assessing the uncertainty of predictions. This article is the last part of a five part series reviewing regular linear-least squares regression. As … Continue reading

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Least-Squares Background Part 4 — Making Predictions

In this Article, I discuss another key use of the regression coefficients, namely to make predictions. This article is part 4 of a 5 part series briefly reviewing some aspects of regular linear least-squares regression. Some background with respect to … Continue reading

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Least-Squares Background Part 3: Assessing the Effects of the X-Variables

In this Article, I discuss the next use of the regression coefficients, namely to try to assess the impact of each of the -variables. This article is the third part of a five part series providing a brief review of … Continue reading

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Background Part 2 — Uses of the Least-Squares Regression Coefficients and Determining Which Variables Matter

In this article, I am going to focus on the most important section of the regression output, namely the table of regression coefficients and the statistics that accompanies them. This article is part 2 of a 5 part series reviewing … Continue reading

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Understanding Logistic Regression Output:
Background Part 1 – Least Squares Regression

As I have indicated previously on this web site, I am going to use regular linear least-squares regression as a starting point for explaining logistic regression. Thus, I will be assuming that you have some familiarity with regular linear regression. … Continue reading

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About Odds and Odds Ratios

From Odds to Probability Related Articles: The Odds Ratio in Logistic Regression The Effects of the X-Variables in Logistic Regression We have all used the word “odds” to describe the probability of something. “Odds are it will rain tomorrow” means … Continue reading

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A Little About Logs

For some reason, which remains mysterious to me, all throughout high school math classes and the first year college math classes (at least in the U.S.), the natural logarithm (the log to the base e) is usually referred to as … Continue reading

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