Online classroom discussion is ubiquitous in higher education today, with both online and hybrid courses. As a result, tools need to be created that enable an in-depth assessment of this medium, thereby facilitating the establishment and support of best practices in education. Such an assessment requires tools for consistent, efficient analysis of discussion content and learning. Because researchers have commonly employed independent coding-based schemes and content analysis to investigate online classroom discussions, comparing studies and conducting meta-analysis of this coding-based research is difficult. To address this problem, this project utilized a literature review identifying 54 distinct coding schemes utilized by 120 primary authors to develop a comprehensive initial set of coding definitions. During this study, iterations of these definitions were applied to over 1500 posts by four coders. Iterative revisions of the definitions were supported by Cohen's kappa reliability assessment, percent representation analysis, definition review, and correlation assessment. Throughout this process, the coding definitions were framed by the community of inquiry model. The final coding scheme provides a reliable analysis tool that synthesizes a range of items of interest to researchers, is grounded in the community of inquiry model, and is applicable to multiple types of online classroom discussion. This set of coding definitions can be efficiently employed as part of any coding analysis. The adoption of this coding scheme by current research efforts will allow results from all studies employing the scheme to be easily compared, speeding the identification of best practices to improve learning for the millions of learners engaged in learning through asynchronous discussion. [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.]