“…As much as possible, effect sizes were calculated for each grade when multiple grades were included within a study (e.g., Lightbown, Halter, & White, 2002). However, many of the studies with participants in multiple grades did not report sufficient statistical information to calculate effect size per grade (e.g., Calderón et al , 1998; Denton, Anthony, Parker, & Hasbrouck, 2004; Slavin & Madden, 1999; Troia, 2004, Waxman, DeFelix, & Martinez, 1994). Literacy strategies produced heterogeneous but statistically detectable mean effect sizes for all educational grades, excluding studies conducted with participants in multiple grades.…”