This study, an in-depth qualitative case study (Stake, 1995), framed with the theoretical tenets of situated learning (Lave & Wenger, 1991) focused on fourth-grade students' experiences in literacy instruction that emphasized agency as a reform tool in response to narrowed, standardized reform efforts that left students disengaged (Au, 2007; 2011; Jackson, 2003; Vaughn, 2020). The student participants, predominately from economically disadvantaged, non-white backgrounds, engaged in literacy participation structures that emphasized broad aspects of their learning, attended to their identity work, and promoted their engagement to illuminate how agency influenced the development of the three outcomes based on situated learning's participation and reification frameworks (Lave & Wenger, 1991; Wenger, 1998). Their experiences have implications for involving students in instructional decision-making to adopt positive learning trajectories and broaden what counts as learning for diverse learners (Delpit, 2012). Findings suggest students deepened their content understanding; their identities shifted through their interactions to negotiate meaning with others, and students linked their engagement in their fourth-grade literacy studies to their future life goals. Moreover, traditional achievement measures were positively impacted by such attention to students' learning, identity, and engagement through their participation in communities of practice and their acts of reification (Lave & Wenger, 1991; Wenger, 1998). [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.]