panel data

Multilevel, Hierarchical, and Mixed Models–Questions about Terminology

October 11th, 2019 by

Multilevel models and Mixed Models are generally the same thing. In our recent webinar on the basics of mixed models, Random Intercept and Random Slope Models, we had a number of questions about terminology that I’m going to answer here.

If you want to see the full recording of the webinar, get it here. It’s free.

Q: Is this different from multi-level modeling?

A: No. I don’t really know the history of why we have the different names, but the difference in multilevel modeling (more…)


Converting Panel Data into Percentiles to Observe Trends in Stata (Part 1)

September 20th, 2016 by

Panel data provides us with observations over several time periods per subject. In this first of two blog posts, I’ll walk you through the process. (Stick with me here. In Part 2, I’ll show you the graph, I promise.)

The challenge is that some of these data sets are massive. For example, if we’ve collected data on 100,000 individuals over 15 time periods, then that means we have 1.5 million cells of information.

So how can we look through this massive amount of data and observe trends over the time periods that we have tracked? (more…)