This paper presents a content analysis of doctoral dissertations in the field of educational technology from 1977 through 1998. Specific research questions include major research themes, how the themes have changed, how the research methodologies have changed, and research trends. The author's "Doctoral Research in Instructional Design and Technology: A Directory of Dissertations, 1977-1998," containing entries for 2,689 dissertations, was used for the study. Initial analysis of the dissertation data showed a wide variety of topics being investigated. Prominent themes included research on computers, instructional development/design and systems, simulation and games, and television and video. Research methodology trends included a reduction in the number of comparison studies, a reduction in the number of experimental studies, and an increase in the number of qualitative studies. Figures present data for each year on: the number of dissertations completed; percentage of dissertations dealing with computers; percentage of dissertations dealing with instructional development, design, or systems; percentage of dissertations dealing with simulation and television; percentage of dissertations dealing with film, videodisc, multimedia, and hypermedia; percentage of dissertations using comparative research methodology; percentage of dissertations using experimental and qualitative research methodologies; programs with the largest number of graduates; and chairpersons with the largest numbers of graduates. (MES)