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Logistic regression

This is a follow up to my previous article on r-squared’s when modeling with logistic regression.  Depending on context in addition to your purpose, a small r squared might be acceptable.  R squared is certainly a worthwhile tool in linear regression because it has a direct translation.  It is the amount of explained variance in…

R-Squareds for logistic regression

Here is a good article about r-squareds (or best proxies for them) for logistic regression. FAQ: What are pseudo R-squareds? This is a subject that seems to be barely discussed and poorly understood.   (Note that I will refer to proxies as r-squareds for ease of discussion). The article gives some excellent insight into the nature…

Changing the way we think about p-values

Let’s break this down.  The article points out the potential for high p-values and gives an example with a high false discovery rate of 86%.  Without looking at the numbers, it seems counter intuitive that the false discovery rate could be 86% when you have a relatively high specificity (95%) and sensitivity (80%).  But let’s…

Sampling and the Presidential Election, part 3 of 3.

In the first part of a three-part series, we talked about some basics with sampling, including some definitions. In the second part, we talked about various types of sampling. In this final installment, we will talk about the Presidential election polls, and important dynamics to consider when taking samples and making inferences.  Before going further,…

Part 2, Types of Sampling

This is the second of a three part series on sampling. The third part will come more quickly than the second part. 🙂 There are four types of sampling.  Simple Random Sample, Stratified, Cluster, and Systematic.  I will give a brief definition as well as an example for each. Simple random sample is the most…

Trying to make sense of all of this

You sure do hear a lot of numbers flying around with respect to COVID-19.  It is often hard to believe (or understand) what you hear from the media, as well as from the experts.  What makes this complex is that there are many factors involved, and it is hard to tease out the importance of…