Sufficient 2. Sufficient information was presented to calculate effect sizes, such as means, standard deviations, t, F,or c values, or the number of people in each group. Articles in which the sample sizes of each group were not cited, lacked any inferential statistical results, or had inferential statistical results but were still inadequate for calculating an effect size according to Lipsey and Wilson (2000) were excluded (e.g., Gleaves, Walker, & Grey, 2007; Langman & Fies, 2010; Purrazzella &