Changing social needs, and especially the rate of change itself, demand a fresh approach to educational theory and practice. Just as theory must draw on the findings of a wide range of sciences, so must practice ensure activity by the student and a reliable system of assessing attainment. Given the constraints to educational development, whether economic or behavioural, the author sees the introduction of educational technology as the only course for improving conditions. He adopts a wide definition of “educational technology”, to embrace a “new applied pedagogical science” and conceives it systemically.