The article is devoted to the scientific and pedagogical activity of the outstanding scientist, teacher, mentor G.N. Alexandrov. The whole life and work of Gleb Nikolaevich Alexandrov, an outstanding person, a talented scientist, a wonderful teacher, is a clear example of serving the high ideals of science, caring for the problems of pedagogy. Gleb Nikolaevich Alexandrov – retired colonel, doctor of pedagogical sciences, professor, full member of the Academy of Pedagogical and Social Sciences (APSN), full member of the International Academy of Sciences of Pedagogical Education (IANPO), corresponding member of the Academy of Natural Sciences, Honored Scientist of the Russian Federation, Bashkortostan, North Ossetia-Alania, Deputy Chairman of the Dissertation Council on Pedagogy, North Ossetian State University named after K.L. Khetagurov. The areas of Alexandrov’s scientific interests are the didactics of high school, cybernetics and pedagogy, the problems of managing the cognitive activity of students, pedagogical qualimetry, the interaction of types of cognitive activity with the leading role of productive, a systematic approach and cognitive activity of students, the foundations of the theory and practice of problem-based and programmed learning, the ratio of algorithmic and heuristic processes, etc.