Common factors are not islands--they work through models: a response to Sexton, Ridley, and Kleiner.

In this article, we respond to Sexton, Ridley, and Kleiner (this issue) from three different perspectives. First, we discuss their criticisms as rooted in a portrait of common factors to which we do not subscribe. Second, we discuss points of agreement and partial agreement between our two articles. Finally, we discuss our areas of clear disagreement with their points of view. In these areas of disagreement we put forth the common factors approach as an empirically supported lens; we discuss the influence of investigator allegiance on the specificity conclusion; and we challenge the idea that the common factors lens is simple. In conclusion, we illustrate how common factors work through a credible therapy model using functional family therapy as an example.