Peer ideas can be valuable contributions to scientific inquiry. Divergent peer ideas can enrich students' thinking and encourage curiosity. Meanwhile, similar peer ideas can promote convergent thinking that can reinforce understanding. However, students need guidance in critically evaluating peer ideas in relation to their own, and in recognizing the influence of peers' ideas. Guided by the Knowledge Integration framework, we explore whether students' perceptions of the impact of peers' ideas align with the revisions made to their written explanations. In a technology-rich, classroom-based inquiry unit on cancer cell division, Grade 7 students (N = 144) investigated the effects of different cancer treatments on cell division, and developed explanations for a recommended treatment. We prompted one group of students to visit a class repository to seek peer ideas similar to their own, and another to seek ideas different from their own. Both groups then revised their recommendations. Based on analyses of students' reflections, initial and revised explanations, and pre and posttests, we found that students prompted to seek divergent ideas perceived peers' ideas to be more impactful, even though both groups of students revised at the same rate and made similar pre to posttest gains. This study suggests a need to attend to students' perceptions of the roles of their peers, particularly in environments designed to reflect authentic processes of the social construction of scientific knowledge.