This article provides a look at the main turning points in research on educational inequalities, both at the level of the field's subject matter and its methodology. The text focuses on authors and concepts that in their time constituted a major innovation, significantly advancing analysis and knowledge in the field of research on educational inequalities. In the article the authors propose viewing researchers in the field of educational inequalities through the lens of their era and in relation to the major turning points between them, which can be identified in terms of subject matter and methodology, and even chronologically. The authors define three basic periods, and for each one present two key concepts. The first period is represented by the basic model of the stratification process and by the socio-psychological model. The second period is characterised by the concept of educational allocation and the theory of 'maximally maintained inequality' (MMI). Presented for the third period are the multinomial transition model and the theory of 'effectively maintained inequality' (EMI). Across these stages of development the authors highlight three of the cited concepts as ground-breaking methodological innovations (the basic model of the stratification process, the concept of educational allocation, and the multinomial transition model) and the other three as innovations in subject matter (interpretive), though closely tied to the advancement of quantitative methods used in the analysis of educational inequalities (the socio-psychological model and the MMI and EMI theories).