Reading Psychology, 31:30–68, 2010 Copyright C  Taylor & Francis Group, LLC ISSN: 0270-2711 print / 1521-0685 online DOI: 10.1080/02702710902733600 UNDERSTANDING AND INTEGRATING MULTIPLE SCIENCE TEXTS: SUMMARY TASKS ARE SOMETIMES BETTER THAN ARGUMENT TASKS LAURA GIL Department of Developmental and Educational Psychology, University of Valencia, Spain IVAR BR ˚ ATEN Institute for Educational Research, University of Oslo, Norway EDUARDO VIDAL-ABARCA Department of Developmental and Educational Psychology, University of Valencia, Spain HELGE I. STRØMSØ Institute for Educational Research, University of Oslo, Norway One of the major challenges of a knowledge society is that students as well as other citizens must learn to understand and integrate information from multi- ple textual sources. Still, task and reader characteristics that may facilitate or constrain such intertextual processes are not well understood by researchers. In this study, we compare the effects of summary and argument essay tasks when undergraduates read seven different texts on a particular scientific topic, find- ing that an instruction to write summaries may lead to better understanding and integration than an instruction to write argument essays. We discuss several pos- sible explanations for this result. We also found that beliefs about the certainty of knowledge in some instances can moderate the effect of task on comprehension performance. In a knowledge society, students are required not only to under- stand single texts but also to understand and integrate informa- tion from multiple textual sources. Thus, students need new lit- eracy skills involved in the processes of reading, comprehend- ing, writing, and using multiple documents (Rouet, 2006), not only for academic success but also in the world outside school. In the last decade, understanding multiple sources and intertex- tual integration processes have received increased attention from Address correspondence to Ivar Br˚ aten, Institute for Educational Research, Univer- sity of Oslo, P.O. Box 1092, Blindern, N-0317 Oslo, Norway. E-mail: ivar.braten@ped.uio.no 30