A third level of educational research is emerging, in addition to original research and secondary-level reviews. Whereas most third-level research syntheses focus on rather restricted topical areas, this study introduces a comparative and integrative overview of prominent second-order research on teaching, including many different types of reviews and aspects of teaching. The purpose of the study is to illuminate patterns in a second-order research topography in the widespread and multi-faceted field of research on teaching from 1980 to the present, in order to discuss its implications for research and review-making. The overview encompasses 75 most-cited reviews of research on teaching published in international, refereed journals from 1980 to 2018 in the Web of Science. The overview utilised a specific coding procedure covering methodology, review topics and context. The study shows that several research traditions have contributed to advances in the research on teaching over time. Reviews have become more formalised, but the distribution of different types of review formats and research traditions is relatively constant. The single most established review format is meta-analysis, but it is less dominant than might be expected in an era of evidence-based education. The reviewers mainly belong to educational psychology, applied linguistics/research on language teaching, or research on science teaching. Whereas most reviews of research on science teaching are qualitative, reviews performed by psychologists and language-education researchers are mainly quantitative or based on mixed methods as a way to rationally and cumulatively summarise and downsize unmanageable amounts of research.