helps students develop their background knowledge, which itself accounts for as much as 33 percent of the variance in student achievement (Marzano, 2000). Background knowledge becomes more crucial in the later elementary grades, as students begin to read more content-specific textbooks (Young, Moss, & Cornwell, 2007) that often include headings, graphs, charts, and other text elements not often found in the narrative fiction they encountered in the lower grades (Sanacore & Palumbo, 2009).