I returned last weekend from the Advanced Training Institute on Health Behavior Theory.  The faculty did an excellent job preparing for all the lectures and the 35 or so students were engaged in the learning experience.  The highlight for me was hearing David MacKinnon, http://www.public.asu.edu/~davidpm/ who was a very entertaining teacher.  While we received a little bit of information on mediation analysis in Dressler and Oths NSF SCRM, you can’t beat hearing from it from the person who wrote the book on mediation analysis.  The key message for me was to make sure you measure the intermediate psychosocial variables if your intervention does not work, you can explore the other causal pathways.