Mixed-methods designs are better suited to unraveling educational phenomena "of enormous complexity" (Berliner, 2002, p. 20). "Because the U.S. education system is so heterogeneous and the nature of teaching and leaming so complex, attention to context is especially critical for understanding the extent to which theories and findings may generalize to other times, places, and populations" (Shavelson & Towne, 2002, p. 5).