This study explored the learning experiences of international students in fully online courses offered through a US university. Employing a sociocultural framework, particularly ideas put forward by Russian psychologists L. Vygotsky and American scholars R. Scollon and S. W. Scollon, the study examined the interplay of host and native cultures in an online learning environment and studied its effect on international students' learning experiences, specifically on the learning experiences of one focal student from China. The research was designed as a two-stage, mixed methods study. Initially a survey was administered to international students who took online courses at a large research university situated in the northeast of the US. Five of the 12 survey participants then completed follow-up online interviews. Cathy, a female graduate student from Shanghai, China who completed the survey and follow-up interviews, was then recruited for an in-depth case study. At the second stage of the study, data related to Cathy's case was collected from several sources--her online American peers, online instructor, and her own observations and reflections. Case study data were gathered from online and face-to-face interviews, reflective journals, and archived online course logs. The cumulative data were analyzed qualitatively and quantitatively, with qualitative data collection and analysis methods having come to take primacy over quantitative methods. During the course of the study it became evident that international students' experiences in US online courses could be concisely described as requiring effort at balancing membership in cross-cutting discourses of the host and native academic cultures. The Scollon and Scollon's concept of multiple discourses enabled this research to suggest that international students' behavior in the classroom is guided by the necessity of balancing multiple discourses; i.e., to follow the expectations and requirements of two or more discourse systems. This necessity affects students' interaction with peers and instructors and manifests itself in communication strategies and linguistic choices. The research findings suggest that learner-centered teaching practices that place emphasis on peer-to-peer learning, as well as course designers' conscious effort to provide space for students' cultures, may help an international student to balance multiple discourses and successfully complete the course. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]