What is it about round numbers that compels us to pause and reflect? We celebrate 20-year school reunions, 25-year wedding anniversaries, 50th birthdays and other similar milestones. I don’t know the answer but the Stata YouTube Channel recently passed several milestones – more than 1500 subscribers, over 50,000 video views and it was launched six months ago. We felt the need for a small celebration to mark the occasion, and I thought that I would give you a brief update.
I could tell you about re-recording the original 24 videos with a larger font to make them easier to read. I could tell you about the hardware and software that we use to record them including our experiments with various condenser and dynamic microphones. I could share quotes from some of the nice messages we’ve received. But I think it would be more fun to talk about….you!
YouTube collects data about the number of views each video receives as well as summary data about who, what, when, where, and how you are watching them. There is no need to be concerned about your privacy; there are no personal identifiers of any kind associated with these data. But the summary data are interesting, and I thought it might be fun to share some of the data with you. Read more…
In my last posting, I introduced you to the concepts of hierarchical or “multilevel” data. In today’s post, I’d like to show you how to use multilevel modeling techniques to analyse longitudinal data with Stata’s xtmixed command. Read more…
In the last 15-20 years multilevel modeling has evolved from a specialty area of statistical research into a standard analytical tool used by many applied researchers.
Stata has a lot of multilevel modeling capababilities.
I want to show you how easy it is to fit multilevel models in Stata. Along the way, we’ll unavoidably introduce some of the jargon of multilevel modeling.
I’m going to focus on concepts and ignore many of the details that would be part of a formal data analysis. I’ll give you some suggestions for learning more at the end of the post. Read more…
For those interested in how pseudo random number generators work, I just wrote something on Statalist which you can see in the Statalist archives by clicking the link even if you do not subscribe:
http://www.stata.com/statalist/archive/2012-10/msg01129.html
To remind you, I’ve been writing about how to use random-number generators in parts 1, 2, and 3, and I still have one more posting I want to write on the subject. What I just wrote on Statalist, however, is about how random-number generators work, and I think you will find it interesting.
To find out more about Statalist, see
Statalist
How to successfully ask a question on Statalist
I just got back from the 2012 Stata Conference in San Diego where I gave a talk on Psychometric Analysis Using Stata and from the 2012 American Psychological Association Meeting in Orlando. Stata’s structural equation modeling (SEM) builder was popular at both meetings and I wanted to show you how easy it is to use. If you are not familiar with the basics of SEM, please refer to the references at the end of the post. My goal is simply to show you how to use the SEM builder assuming that you already know something about SEM. If you would like to view a video demonstration of the SEM builder, please click the play button below: Read more…
StataCorp now provides free tutorial videos on StataCorp’s YouTube channel,
http://www.youtube.com/user/statacorp
There are 24 videos providing 1 hour 51 minutes of instructional entertainment: Read more…
The topic for today is drawing random samples with replacement. If you haven’t read part 1 and part 2 of this series on random numbers, do so. In the series we’ve discussed that Read more…
Last time I told you that Stata’s runiform() function generates rectangularly (uniformly) distributed random numbers over [0, 1), from 0 to nearly 1, and to be precise, over [0, 0.999999999767169356]. And I gave you two formulas,
- To generate continuous random numbers between a and b, use
generate double u = (b–a)*runiform() + a
The random numbers will not actually be between a and b: they will be between a and nearly b, but the top will be so close to b, namely 0.999999999767169356*b, that it will not matter.
- To generate integer random numbers between a and b, use Read more…
I want to start a series on using Stata’s random-number function. Stata in fact has ten random-number functions: Read more…
Stata 12’s new import excel command can help you easily import real-world Excel files into Stata. Excel files often contain header and footer information in the first few and last few rows of a sheet, and you may not want that information loaded. Also, the column labels used in the sheet are invalid Stata variable names and therefore cannot be loaded. Both of these issues can be easily solved using import excel. Read more…