Re: Positive loadings with PROMAX, negative with OBLIMIN

Posted by Rich Ulrich on Nov 09, 2013; 4:32pm
URL: http://spssx-discussion.165.s1.nabble.com/Positive-loadings-with-PROMAX-negative-with-OBLIMIN-tp5722956p5722967.html

[re-post, in case you did see the first.  Slightly re-worded.]
As everyone says, the  +/-  direction of the vector is wholly
arbitrary and irrelevant to the meaning. 
 
A method of solution results in a set of signs; a slight variation
in the method (or data) might readily result in reversed signs.

I remember a convention suggested for how-to-display solutions:
compare the sums of negative and positive loading-squared terms,
and switch all signs if the negatives are bigger.  That could be a
standard either for programming or for data presentation in reports.  
"Eyeballing" usually gives an easy answer for Varimax.

Oblique rotations give larger loadings in general.  Simplified
standards for eyeballing include, "Make the largest loading
positive" and "Make the majority of loadings positive."

I wonder, but not very much, how many computer programs implement
any of these rules of thumb.

--
Rich Ulrich

> Date: Sat, 9 Nov 2013 05:46:03 -0800
> From: [hidden email]
> Subject: Re: Positive loadings with PROMAX, negative with OBLIMIN
> To: [hidden email]
>
> Thanks to Art, David & Mike. That's helpful.
>
> ...