In 2004, Saunders, Berliner and Hanson developed a system of categories for social work interventions which has proved somewhat controversial. In their first analysis, holding therapy was placed in Category 6 as a "Concerning treatment". In 2006 Craven and Lee classified 18 studies in a literature review under the Saunders, Berliner & Hanson system. They considered both dyadic developmental psychotherapy and holding therapy. They placed both in Category 3 as "Supported and acceptable". This categorization by Craven and Lee has been criticized as unduly favorable, a point to which Craven and Lee responded by arguments in support of holding therapy. Both Myeroff et al.'s study and Becker-Weidman's first study (published after the main Report) were examined in the Task Force's November 2006 Reply to Letters and were criticized as to their methodology. Becker-Weidman's study was described by the Task Force as "an important first step toward learning the facts about DDP outcomes" but falling far short of the criteria necessary to constitute an evidence base.