By I am ex-cardnity Brown and Sitzmann 2011 additionally critiques the literature and emphasizes research on the processes which are required to guarantee that coaching benefits emerge. Arthur, et al. 2003 meta-analyzes the literature on coaching effectiveness. Russ-Eft 2002 proposes a typology of coaching designs. Salas, et al. 2012 offers recommendations for evidence-based coaching follow.