FAQs about Statistical Interactions 

 I am writing a short essay about the connection and distinction between indirect effect and interaction effect for a methodological class and find the following website very helpful to clarify some of the FAQs on that subject. The website is maintained by Professor Regina Branton at the Department of Political Science of Rice University.  

  http://www.ruf.rice.edu/~branton/interaction/faqshome.htm  

 Also check out the mediation item at Wikipedia and its great references. 

  http://en.wikipedia.org/wiki/Mediation_(statistics)