An anonymous reader posted [the following question on my blog](http://jeromyanglim.blogspot.com/2009/11/tips-for-writing-up-research-in.html?showComment=1285227037363#c3803430820186070755).

**Context:** 

The reader wanted to run a factor analysis on scales from a questionnaire - but the data was from paired husbands and wives. 

**Question:** 

* Can factor analysis be run on dyadic data? If so, how?
* Would the independence assumption hold for factor analysis?