informal scientific writing

On the plane home, I answered a detailed question from Jannuzi (NOAO), in the form of a few-page typeset document, started work on an answer to a detailed question from Abate (NOAO), and wrote a few pages about probabilistic reasoning for the next installment in the Data Analysis Recipes series. My conversation yesterday with Jannuzi convinced me that it would be useful to review the basic operations available in measure theory (probability calculus). Most of the things we do here at Camp Hogg in data analysis boil down to simple applications of simple operations in measure theory; it isn't hard, but it is powerful, in the sense there are a few rules that—once you learn them—make every novel probabilistic inference straightforwardly discoverable. I also want to advertise the dimensional-analysis way of thinking about probability theory, which has been very useful to me (and Rix too, I think).