This study investigated the effects of prior attitudes on how students deal with conflicting information in multiple nonlinear texts. Sixty-one Dutch 11th grade students read multiple texts on a controversial topic and wrote a short essay on it. These essays were scored on perspective taken and the origin of information included in them. Ordinal regression analysis showed that students with strong prior attitudes were significantly more likely to write essays that were biased towards their prior attitudes. Furthermore, multiple regression analyses revealed that students with strong attitudes took explicit stances and added large proportions of information not presented in the reading materials in their essays, whereas students with neutral attitudes wrote syntheses and borrowed more information from the materials. Overall, results show that prior attitudes can bias how students deal with conflicting information in an open-ended reading and writing task. (C) 2013 Elsevier Ltd. All rights reserved.