I am teaching a class, Introduction to R (MEDB 5505). Here is the syllabus for Fall Semester 2017. Continue reading

# Category Archives: Statistics

# PMean: Syllabus for Introduction to SPSS, Fall semester 2017

I am teaching a class, Introduction to SPSS (MEDB 5506). Here is the syllabus for Fall Semester 2017. Continue reading

# PMean: Open source as a budgetary measure

Like a lot of public universities, UMKC is having a lot of financial difficulty. They are asking for advice from faculty members on how to address this budget shortfall. Not being the bashful type, I suggested that we stop paying commercial software vendors and commercial journal publishers and rely instead on open source. Here’s the details of my letter. Continue reading

# PMean: A quick summary of my research

I might be giving a very brief (5 minute) overview of my research for students in the Department of Biomedical and Health Informatics. Here are some details of that work, with links if anyone wants to dig deeper. Continue reading

# PMean: Conferences for learning R

I heard about a new series of conferences for learning about R. I have not attended any of them, but they look interesting. Continue reading

# PMean: What are the important packages for R

I got a question from one of the students in my “Introduction to R” class asking what are the important packages for R. That’s a hard question to answer, but if I got only easy questions, they wouldn’t be paying me the big bucks. Here’s what I think. Continue reading

# PMean: It only looks like a blank

I was having trouble with trailing blanks in an R program. There were some strings that looked like ” Y” and “Y ” and it’s easy enough to fix this, but one of the “Y ” values was not converting properly. The second character wasn’t a blank, but it looked like it. Here’s what I had to do. Continue reading

# PMean: A p-value of .000

Dear Professor Mean, I ran a statistical test in SPSS and got a p-value of .000. I re-ran the same data in Microsoft Excel and got a p-value of 3.9433E-9. I know from scientific notation that this is the same as 0.0000000039433. Why are these numbers different? Continue reading

# PMean: Extremely imbalanced multi-center trials

There was some recent discussion of issues with multi-center trials where one center dominates, contributing as much as 94% of all the patients. What does this do to the generalizability of the study. I wanted to summarize these comments here, because it relates to some of the issues I’m looking at right now in accrual models for multi-center trials. Continue reading

# PMean: Getting out of the free consulting trap

Someone on the Statistical Consulting Section message board asked a question about how to handle a situation where a colleague was repeatedly asking for advice. How do you make a transition from offering free advice to getting paid as a consultant? There were lots of good answers, and here’s the suggestion that I offered. Continue reading