Jacquelines of all trades or masters of some?  Negative implications of focusing on common factors. 
The emphasis on common factors initially grew out of increasingly frustrating findings from randomized clinical trials that head-to-head comparison of different treatments rarely found one to be superior (Luborsky et al.,  2002; Luborsky, Singer, & Luborsky, 1975).  In this regard, Cameron and Keenan (2010) have done well calling attention to a fundamental problem we deal with in researching, practicing, and teaching.  As an instructor, it is difficult to teach practice- minded MSW students about empirically supported treatments when, with few exceptions, most theoretically distinct treatments that have been contrasted are not so different in terms of outcomes.  This beckons us to teach students to think critically and understand the limits of current research on empirically supported treatments.  However, I have argued here that there are benefits to teaching students about specific ESTs.  It is plausible that providing extensive training in specific ESTs could be a platform for teaching about common factors, rather than focusing on developing generalist skills and later learning specific techniques that are needed in certain practice areas.  Doing so gives students some useful techniques, which are associated with clinical improvement and can be adapted to other practice settings.  It is unclear if the same can be said for teaching a common factors approach, which is already the dominant training model in social work.  Of course, empirical research is needed to determine whether varying degrees of training emphasis on common factors or specific ESTs affect clinical skill development or adoption of ESTs.  With regard to the issue of common factors in clinical research, health services researchers are already being encouraged to propose novel techniques for how we might affect common factors.  Although it is clear that such mechanisms are not always unique to particular treatments, such research is typically being done incrementally by studying in-session processes operating within particular treatments or by isolating the relative contribution of elements of evidence-based treatments.  Such studies can identify important techniques that are useful in clinical practice in multiple contexts, which then can be taught to practitioners.  It is unclear if the study of general common factors can produce information that validates the use of particular techniques or if such research is compelling enough for stakeholders to accept unspecified eclectic practice as empirically supported.  In conclusion, training on specific ESTs may be an ideal goal in social work education, and the common factors research most likely to inform practice will probably be done in the context of studying specific ESTs.  Additional research is needed on the barriers that impede such training and whether such efforts result in more wide-spread adoption of EBPs in social work practice.  Compared with focusing on a transtheoretical common factors approach, any movement toward teaching specific ESTs in the classroom would truly be a paradigm shift.