Citations allow researchers to define relationships across articles and develop arguments by building on the work of others. This study explores citation of theory symbols in Instructional Design and Technology (IDT) academic articles. The term theory symbol is used to define a concept that, after its original publication, is subsequently incorporated by later writers through citation. Exploring the citation history of the seminal publications makes it possible to trace theory symbol use over time and thus to trace its dissemination in the field. A typology of theory symbol use in IDT academic publication is developed through a citation context analysis (CCA) of a sample of articles published in Educational Technology Research and Development (ETRD) and its predecessor journals (1953–2012) which incorporate theory symbols through citation. This analysis contributes to an understanding of how theory has shaped IDT disciplinary knowledge and augments discourse analysis and bibliometrics by examining the context in which theory is incorporated into academic publication. / Ph. D. / This study explores the citation of theory symbols in Instructional Design and Technology (IDT) academic articles. A <i>theory symbol</i> is a concept that is included in a publication deemed to be foundational to a theory’s creation or development and subsequently incorporated by later writers through citation. Exploring the relationships between these cited and citing documents, with specific attention to the content of prior work passed from one to the other, makes it possible to trace the dissemination of theory symbols in the field and develop a typology of theory symbol use in IDT academic publication. This process is called citation context analysis (CCA) (Ritchie, 2008). A sample of articles published in <i>Educational Technology Research and Development</i> (ETRD) and its predecessor journals (1953–2012) serves as the foundation of the study. This analysis contributes to an understanding of how theory has shaped IDT disciplinary knowledge by examining the context in which theory is incorporated into academic publication. As Baskerville and Dulipovici (2006) argue, it is valuable to understand the application of theory because theory is used to support research arguments, methodology and in turn the development of other theories.