Factor Analysis Tips: Unexpected Things I Learned at SAS Global Forum

Are you still re-ordering your factor pattern by sorting columns in Excel? Well, do I have a tip or two for you.

The cool thing about some large conferences is that even the things you hadn’t planned on attending can be worth while. For example, during one time slot, I didn’t have anything particular scheduled and Diane Suhr was doing a talk on factor analysis and cluster analysis. Now, I published my first paper on factor analysis in 1990, so I was mostly interested in the cluster analysis part.

After all of those years, how did I not know that PROC FACTOR had an option to flag factor loadings over a certain value? Somehow, I missed that, can you believe it?

I also missed the REORDER option that reorders the variables in the output from largest to smallest on their loading on the first factor, then in order of their loading on the second factor and so on.

It’s super-simple. Use FLAG = value  to flag loadings and REORDER to reorder them, like so.

proc factor data=principal n=3 rotate=varimax scree FLAG=.35 REORDER ;
var X1 x2 x3 x4;

You can see the results below. With a small number of variables like this example, it doesn’t make much difference but in an analyses with 40 or 50 variables this can make it much easier to identify patterns in your data.

I am backwards woman. I write about statistics and statistical software in my spare time and my day job is making video games. In my defense, the latest series of those games teaches statistics – in Spanish and English.