As enrollment in K-12 online courses continues to grow, there is a need to ensure students are enrolled in quality online courses and that online courses provide an educational experience comparable to their face-to-face equivalents. Thus, this study investigated teachers' views of the quality of online courses at state virtual schools. In designing this study, I developed a conceptual model of quality indicators gathered from the K-12 Quality Matters Rubrics, the Community of Inquiry framework, and the research literature. Using a complementarity mixed-methods approach, I invited state virtual school teachers, who also had experience teaching face-to-face courses, to respond to an electronic survey questionnaire consisting of eleven demographic questions, 43 quality indicator questions, ten online and face-to-face comparisons questions, and two open-ended questions. I used findings from five research questions to inform the quality of online courses at state virtual schools. Results of the study suggested about teachers felt one in six state virtual school courses are well-designed and need little improvement. Findings also indicated participants felt most (39 out of 43) quality indicators were present to at least a reasonable degree in most state virtual school courses. Quality indicators less likely to be present included proctored tests and exams, student-student interaction, direct instruction, and items related to continuous improvement. When viewed with respect to curriculum alignment, findings suggested the assignments/activities and assessments in some courses may not be effectively aligned to the learning objectives. While most teachers felt that student outcomes were equally likely to occur in both online and face-to-face courses, approximately 25% of state virtual school teachers believed students learn more in face-to-face situations. Results also indicated state virtual school teachers perceived online assessments and teachers' responsibilities to be most related to student outcomes in state virtual school courses. State virtual school teachers also offered recommendations to improve the quality of state virtual school courses. Indicators with the greatest number of recommendations related to course assignments/activities, continuous improvement, course interaction, and assessments. Unanticipated findings suggested learner characteristics and mentors may play an even greater role than expected in student success in state virtual school courses. [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.]