This is the third and last part of my attempt to explain logistic regression in pictures. You can see a picture of odds ratios here, and a picture of two charts of predicted probabilities, to compare models, here. If people only know one chart associated with logistic regression, it is usually the ROC chart, though…
I tweeted that I believed one could explain logistic regression results in three or four charts, and Alberta Soranzo tweeted back, “Try me.” Challenge accepted. These data are taken from the Kaiser-Permanente study of the Oldest Old, a sample of 5,986 people who were aged 65-95 when recruited into the study. Participants were followed for…
If you have a mad desire to do logistic regression with SAS On-Demand with SAS Enterprise Guide, here is a movie that shows how to do it. It is a .avi file so you may want to just download it and run it on your PC. Here is why the movie is not all that…
When people ask me what type of statistical software to use, I run through the advantages and disadvantages, but always conclude, “Of course, whatever you choose is going to give you the same results. It’s not as if you’re going to get a F-value of 67.24 with SAS and one of 2.08 with Stata. Your…
All my programs are working today and I am sad. Fortunately for everyone else, but unfortunately for me today, SAS has increasingly automated or semi-automated fixing those errors. It’s unfortunate for me because I wanted to talk about errors and how to fix these. I could create a simulation dataset but I hate doing that….
My friend, Gokor Chivichyan, a mixed martial arts instructor, once gave this questionable advice to his students, “Women usually just say they’re fat to get attention. So, me, I agree with them. If she says she’s fat, I say, yes, you fat but we like you anyway. If she’s really fat, though, you just have…
The #reverb10 prompt for December 3rd was to write about a time when you felt most truly alive in 2010. There were more prompts, about what you wonder about and other examining-your-soul type of introspection. This isn’t that kind of blog. I don’t think I’m that type of person. For the record, the time I…
Going from the phi coefficient to odds-ratios. Remember the numerator for the phi coefficient was well, the odds ratio is the same two numbers DIVIDED rather than subtracted. You might think it is four numbers, but really it is not. The first number is the product of the diagonal cells (see below). The second number…
There are actually 5 strengths you need to be a successful statistical consultant; communication, testing, statistics (duh), programming and general knowledge outside of your field.
I’ll be speaking about being a statistical consultant at SAS Global Forum in D.C. in March/ April. While I will be talking a little bit about factor analysis, repeated measures ANOVA and logistic regression, that is the end of my talk. The first things a statistical consultant should know don’t have much to do with…