Adapting to and participating in technology-enhanced classrooms is challenging for both students and teachers. An emerging need in K-12 STEM classrooms is to investigate how students and teachers use learning technology to engage and practice scientific inquiry. Recent researchers have focused on designing orchestration technology to assist teachers in understanding multidimensional interactions. Nevertheless, more empirical research is needed in K-12 STEM education to examine inquiry learning and facilitation through learning technologies and tools, especially in computer-supported collaborative learning environments. My research investigates the instructional trajectory of a teacher from the professional development phase through classroom facilitation and retrospective reflection, as well as how dyads engaged in collaborative scientific inquiry by playing a narrative-based game using a variety of mediating tools. My work can contribute to a deeper understanding of complex classroom discourse and instructional practices, thereby enriching research on supporting classroom orchestration and inquiry learning in technology-enhanced K-12 STEM classrooms. My dissertation consists of three articles, each of which investigates the role of learning technology in promoting classroom interaction and teacher facilitation from a distinct viewpoint. Students in a middle school STEAM program participated in this study to microbiology content through playing a narrative-based video game. Multiple data sources were collected, including trace log, classroom data, interview data and artifacts from students. The first paper explores how the teacher orchestrated classroom practices and adapted facilitation goals and strategies with the use of mediating tools. The second paper investigates the decision-making process of a teacher using a combination of semi-structured interviews and video-stimulated recall interviews to understand his pedagogical intentions and underlying decision-making process. The third study examines how dyads practiced scientific discourse and regulated their inquiry process in game-based learning environment. [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.]