“…Seven out of the 11 effectiveness studies recruited control groups (Cooper, Arnold, and Boyd 2001;Cooper and Whitebread 2007;Gerrard 2005;Reynolds, MacKay, and Kearney 2009;Sanders 2007;Scott and Lee 2009;Seth-Smith et al 2010), 6 of which were matched to some extent (Cooper, Arnold, and Boyd 2001;Cooper and Whitebread 2007;Reynolds, MacKay, and Kearney 2009;Sanders 2007;Scott and Lee 2009;SethSmith et al 2010). Reynolds, MacKay, and Kearney (2009) The time between pre and post scores varied from three months (Doyle 2005) to one year (Cooke, Yeomans, and Parkes 2008;Cooper, Arnold, and Boyd 2001). However, one study (O'Connor and Colwell 2002) provided follow-up data for 12 of the children who had attended an NG, at a mean of 2.67 years since leaving the NG.…”