The purpose of the study is to examine positions of students and a teacher in dialogic discussion. In this study, dialogic discussion was defined with Bakhtin's (1981) dialogism, Nystrand's (1997) explanation of dialogically organized instruction, and Mercer's (1995) explanation of Exploratory Talk. Studies about literature discussion in elementary levels have heavily focused on students' individual responses, but have not paid attention to students' positioning. In this study, positioning theory (Harre & van Langenhove, 1999) was employed to investigate positioning in dialogic discussions. This study was designed to be a qualitative study. Data were collected in a third-grade classroom over five months from multiple sources, such as literature discussion transcripts, interviews, field notes, analytic memos, etc. Classroom discourse analysis (Bloome et al., 2005) was adapted for analyzing selected transcriptions. Two lower-achieving students, and two higher-achieving students were selected as focal students for closer analysis of students' positioning. The findings showed that all four focal students exhibited the positions of contributor and informer most frequently. Dialogic moments were significant for the lower-achieving students because they generated reason-supported thinking more often than in non-dialogic moments. The positions of challenger and negotiator were mostly exhibited by higher-achieving students in dialogic moments. However, compared to other positions, these positions were less frequently exhibited. The findings also revealed that the students' positioning was closely related to the teacher's positions and instructional strategies. In this study, the teacher's actions facilitated students to be contributors and informers, but did not explicitly ask them to be challengers and negotiators. Additionally, the finding showed that the teacher exhibited different positions to make a discussion dialogic. Once a moment became dialogic, the teacher mainly exhibited the position of manager and kept the discussion going smoothly. In this study, the focal students made shifts in their positions between help-seekers and teacher-like figures. The lower-achieving students sought help during dialogic moments and received help from their peers. However, when the higher-achieving students sought help, they either did not receive help from their peers or were not satisfied with the peers' answers. Therefore, they sought help from the teacher. When the teacher stepped back during dialogic moments, the higher achieving students became teacher-like figures and managed the discussion instead of the teacher. This study has methodological and pedagogical implications. First, this study implies the usefulness of positioning theory when examining dynamics in literacy events in a classroom. Second, this study implies that teachers need to teach students explicitly how to challenge one another until students are able to do so without prompting. Teachers also need to monitor students' positioning to find out whether certain positions are taken by only certain students or not. If this is the case, teachers can intervene in the students' talk and disrupt the norm that is established among students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]