I’m working on a project where the researchers need a case-control study, though they may not know that yet. I want to show them what a case-control study gives them that would not be available with other methods. But I need to come up with a reasonable control group for the case-control design. It doesn’t have to be perfect, but it can’t be a totally stupid control group either. This article is the classic reference on the theoretical principles that underlie the selection of controls in a case-control study. Continue reading
Monthly Archives: February 2016
PMean: The need for documentation standards
I’m working in a team programming environment and I would have to characterize the quality of the documentation as uneven. I’m going to make the case for having detailed documentation standards at a meeting tomorrow. Here’s the a general overview of what I will say. Continue reading
PMean: The problem with incentivizing
I came across a question, “How does your institution incentivize researchers to write more grants?” that was posted a while ago. I felt it was too late to respond directly, but I did want to mention something in my blog about this. “Incentivize” is one of those awful words that used to be a noun (incentive) but has been changed to a verb to make it sound more trendy. That’s something to dislike from the very start, but I have an even greater gripe about incentivizing. Continue reading
PMean: Recent (and not so recent) advances in statistical computing
I’m giving a talk to the Statistics students at the University of Central Missouri. Here’s the title and abstract of my talk. Continue reading
PMean: My latest short biography
I am giving yet another talk and wanted to take some time to update my earlier short biography. Continue reading
PMean: Searching through a mess of files
I am working on a project that has a series of files in R and R Markdown, and I need to track down where a particular function was originally defined. In Unix based systems, this is pretty easy to do. Continue reading
PMean: Business essentials that you need to know before starting your career as an independent statistical consultant
I am giving a presentation on the business essentials that you need to know before you start a career in independent statistical consulting. Here is a summary of what I’ll be talking about. Continue reading
PMean: Simulating power for a test of association in a two by two table
In an earlier blog post, I slogged through the calculation of power for a test of association in a two by two table. You can also approximate power using a simulation. It is done quite easily in R, but I want to show it in SPSS. Why? Just because. Continue reading
PMean: Calculating power for a test of association in a two by two table
A colleague was curious to see the formulas behind the power calculations done by many statistical software programs and online calculators. In particular, she wanted to see the formula used for power of the Chi-squared test of association in a two dimensional contingency table. It gets pretty messy for anything larger than a two by two table, but even a two by two table is a bit tricky. Here ins one mathematical approach that you can choose for a power calculation. Continue reading
PMean: A rant about the “reader pays” model of publication
Something came up in our department about a predatory pay for access journal that was soliciting support. All the appropriate warnings were made (there’s a nice explanation of predatory open access publishing at Wikipedia, if you’re curious). But I felt that I had to made a strong defense of the value provided by legitimate open access publishers. Here’s a summary of what I wrote. Continue reading