This dissertation consists of two manuscripts to examine student motivation and engagement in the foreign language classroom. The purpose of the first paper is to propose a model that distinguishes between motivation and engagement. The paper highlights the connections and differences between motivation and engagement in order to point out issues including: whether motivational studies differ from engagement studies; whether the definition of motivation differs from the definition of engagement; and whether students can be motivated but not engaged in language class. In the model, motivation is defined as a general perception of content, discipline area, or activity that influences attitudes toward task involvement. Engagement is seen as a person's involvement in a task. The model also suggests relationships between motivation and engagement. It can be used by both researchers and practitioners to explore the importance of both concepts to student achievement. The purpose of the study in the second paper is to investigate task engagement perception gaps among course designers, teachers, and students in a technology-enhanced language classroom using the model proposed in the first paper as a framework. Based on the findings, the model was refined to help teachers and course designers have a better idea of how to choose and create engaging tasks for students. A sample of 29 pre-service teachers, three online course designers, and two instructors was recruited to participate in an online Chinese course to express their perceptions on these online tasks. All the participants were asked to take a background information survey and six weekly engagement surveys. Interviews, artifact analysis, and observations were also conducted to provide additional insights into participants' background, the tasks, and their perceptions of these tasks. The findings suggested a clear distinction between emotional and behavioral engagement from the student engagement indicators in the proposed model. Furthermore, several categories under the cognitive engagement were modified to make more sense for technology-enhanced language classrooms. Taken together, these findings might be helpful for teachers and course designers to indicate students' emotions and behaviors, and then adjust the teaching strategies and learning environments to sustain or increase students' task engagement. [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.]