FAQ: What is the coefficient of variation? Situations and Definitions A coefficient of variation (CV) can be calculated and interpreted in two different settings: analyzing a single variable and interpreting…
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FAQ What is complete or quasi-complete separation in logistic regression and how can I deal with them?
Occasionally when running a logistic or a multinomial logistic regression we would run into the problem of so-called complete separation or quasi-complete separation. On this page, we will discuss what…
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FAQ What is complete or quasi-complete separation in logistic/probit regression and how do we deal with them?
Occasionally when running a logistic/probit regression we run into the problem of so-called complete separation or quasi-complete separation. On this page, we will discuss what complete or quasi-complete separation is…
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FAQ: How can I determine the correct error term in an ANOVA?
<!- 12/7/07 — pbe –> One method for determining correct denominators in analysis of variance is the Cornfield-Tukey method. This FAQ presents a modified version…
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FAQ: What’s with the different formulas for kurtosis?
In describing the shape statistical distributions kurtosis refers to the “tailedness” of a distribution. Different statistical packages compute somewhat different values for kurtosis. What are the different formulas used and…
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FAQ How do I interpret a regression model when some variables are log transformed?
Introduction In this page, we will discuss how to interpret a regression model when some variables in the model have been log transformed. The example data can be downloaded here…
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FAQ: How are the likelihood ratio, Wald, and Lagrange multiplier (score) tests different and/or similar?
Purpose: This page introduces the concepts of the a) likelihood ratio test, b) Wald test, and c) score test. To see how the likelihood ratio test and Wald test are…
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FAQ: How do I interpret odds ratios in logistic regression?
Introduction When a binary outcome variable is modeled using logistic regression, it is assumed that the logit transformation of the outcome variable has a linear relationship with the predictor variables. …
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FAQ What is complete or quasi-complete separation in logistic regression and what are some strategies to deal with the issue?
Occasionally when running a logistic regression we would run into the problem of so-called complete separation or quasi-complete separation. On this page, we will discuss what complete or quasi-complete separation…
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FAQ: How can I detect/address spatial autocorrelation in my data?
Commonly used statistical approaches often assume that the measured outcomes are independent of each other. In spatial data, it is often the case that some or all outcome…
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