AbstractsBiology & Animal Science

Far too many children begin school with large knowledge gaps that, when left unaddressed, widen and contribute to long-term reading comprehension failure (Hart & Risley, 1995). Early knowledge gaps are often rooted in opportunity gaps (i.e., accumulated inequities in access to key educational resources), with text being a key resource for knowledge acquisition (Stanovich & Cunningham, 1993). Text is particularly important for building knowledge that enables expository text comprehension because much ofthis knowledge is abstract and far removed from everyday experiences. However, there are differing views regarding which text genre or combination thereof best develops the knowledge that enables expository text comprehension. Without clear guidance, text anthology publishers and teachers likely will continue employing uneven text selection methods and knowledge gaps will persist. Thus, identifying optimal text selection is essential if we are to reduce the opportunity gaps underlying poor reading comprehension achievement. Towards this end, I examined effects oftext genre on first-graders' conceptual knowledge and comprehension growth using a cluster-randomized design. Children (N = 57) were randomly assigned to informational narrative and expository text (C, n = 26) or expository text only (E, n = 31) groups. Both C and E children received the same five- week read-aloud intervention. Instruction was organized around a central science conceptandusedtopically-relatedtext. Keyfeaturesincludedexplicitvocabulary instruction, semantic word sorts, scaffolded discussions, and application to new contexts. Results suggest that use of both texts facilitated: (1) greater gains in knowledge breadth and depth (but not statistically significant); (2) greater gains in comprehension depth (gains for narrative text were statistically significant); (3) a significantly larger increase in conceptual knowledge and narrative text recall accuracy and a larger increase in expository text recall accuracy; (4) sustained effects as C children demonstrated continued knowledge and comprehension growth six weeks after the intervention concluded. Findings suggest that effective use ofa combination ofnarrative and expository text may contribute to a reduction in early opportunity and knowledge gaps, and that both types of text should be considered in content area curricular and instructional decision making.