I was attending a short course taught by Susanne May on clinical trials (very good, by the way) and she mentioned an interesting publication. It talks about the “random high” bias. Continue reading

# Monthly Archives: October 2015

# Quote: That’s not an experiment…

Referring to anecdotal data: “That’s not an experiment you have there, that’s an experience.” Sir Ronald A. Fisher.

# PMean: How many research subjects…

Here’s a quote from yours truly. I’ve added a cute graphic from the public domain (downloaded from www.pixabay.com) to liven it up a bit. Continue reading

# PMean: How big is my graph?

When you are drawing a graph in R, sometimes you have to check how big things are before you can do anything else. There are many different ways of measuring size. Here are some simple examples. You can find the R Markdown code that created these examples here. Continue reading

# PMean: Nonlinear regression for the difference of two exponentials

I wanted to provide an overview of how you analyze a classic nonlinear regression model. It is a difference of two exponential functions. This nonlinear function is used commonly in pharmocokinetic models and is a simply way to model the oral administration of a drug. I want to show how the model works in a mathematical sense and then how you fit it using R. Continue reading