Intraclass correlation associated with therapists: estimates and applications in planning psychotherapy research. by Baldwin, SA, Murray, D, Shadish, W, Pals, S, Holland, J, Abramowitz, J, Andersson, G, Atkins, D, Carlbring, P, Carroll, K, Christensen, A, Eddington, K, Ehlers, A, Feaster, D, Keijsers, G, Koch, E, Kuyken, W, Lange, A, Lincoln, T, Stephens, R, Taylor, S, Trepka, C, Watson, J