Knowledge development, application, and refinement are essential parts of students' reading. One way to observe how students use their knowledge as they read is through talk. Studies routinely indicate that though reading is a social endeavor, teachers spend most of the allotted instructional time talking or using discourse patterns that do not promote critical or analytical thought about text. Additionally, teachers appear to rely on content knowledge, previously taught knowledge, and their own experiences to facilitate lessons rather than the diverse knowledge their students have. In response to these findings, this study examined how a sixth grade English language arts co-teaching team implemented a dialogic protocol called Spider Web Discussions using conceptually-coherent texts or a selection of texts on a similar theme (TB-SWDs), designed to support students' knowledge expression and co-construction for productive classroom discourse. The present study investigated the following research questions: (1) what are the affordances and challenges of using Spider Web Discussions in a sixth-grade language arts context?; (2) in what ways do sixth-grade students apply feedback from previous Spider Web Discussions to subsequent discussions?; and (3) how do students use knowledge, rigorous thinking, and discussion structures to engage in meaning-making with peers though Spider Web Discussions? To answer these questions, I conducted a multiple-case study to analyze students' interactions and classroom discourse. Eight discussions were video-recorded and analyzed from five class periods over the course of four months. In total, 147 minutes of observational data were collected across the eight recordings. Videos were coded for the lessons using provisional codes of types of knowledge, and analyzed for knowledge development, rigor, and discourse interactions between and among teachers/students. A researcher-developed tool called the Knowledge Assessment for Talk through Comprehension (the KAT-C) was deployed to assist with the analysis. In the study, it was observed that TB-SWDs provided many affordances, including social, academic, and management concepts. Additionally, many challenges such as control and individualistic tendencies were also observed. Within the TB-SWD, students frequently used multiple kinds of knowledge and social supports, engaging with a variety of different discussion structures. Additionally, students showed growth in how they used text evidence to support their knowledge co-construction and revision. This study brings to the forefront the need for student-led discourse opportunities where teacher intervention is limited to support agency and higher-order thinking. When students can engage independently in knowledge-centric discussions about text, they can utilize nuanced, higher-order thinking and develop a more comprehensive understanding of text. These discussions would not have the same richness if they were facilitated in traditional teacher-facilitated settings where a certain answer is expected. This study contributes to the field's understanding of both student-centered classroom discourse (i.e., where the teacher has a minimal or observer role) and how students use knowledge in-the-moment to make meaning from text through talk. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]