Thesis advisor: Curt Dudley-Marling / This qualitative dissertation, informed by sociocultural theory (Gee, 1996; Vygotsky, 1978), examines how a fourth grade teacher and his students learned to participate in Shared Inquiry, a discussion practice where students learn how to build an evidential argument, including a claim that is supported by evidence and justified by a warrant (Toulmin, 1969). Students also learn how to weigh the merits of opposing arguments and how to modify their initial opinions as evidence demands. Over the course of ten weeks, the fourth grade teacher implemented Shared Inquiry as part of the Junior Great Books (JGB) program, offered as a supplement to a district mandated reading program. The teacher was observed while using the JGB program and while providing instruction through the mandated reading program. He participated in action research (Stringer, 2007) to examine how to make Shared Inquiry most successful. This dissertation describes how the teacher's action research enabled his students to become successful with Shared Inquiry, after they initially struggled with the practice. Over time, they learned a new way of engaging, not only with literature, but also with fellow classmates. This dissertation also describes how the fourth grade students learned a different set of literacy practices through the mandated reading program. The argument is made that Shared Inquiry has the potential to be a far more substantively engaging (Nystrand, 2006; Nystrand & Gamoran, 1991, 1997) literacy practice compared to the mandated reading program. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.