This chapter provides an overview of national and international studies conducted in order to test the validity of recent theoretical models of Educational Effectiveness Research. It aims to develop further the Dynamic Approach in order to explain in a more precise way the qualities that the Advisory and Research Team needs in order to support teachers and schools in becoming more effective in terms of promoting both quality and equity in education. The 2020 version of the dynamic model has the following six main characteristics. Firstly, the early version of the dynamic model was multilevel in nature since its factors were situated at four different levels: student, classroom, school and system/context. An essential difference between the dynamic model and all the previous models is its attempt to look at the qualitative characteristics of factors and to provide more precise feedback on how the functioning of factors can be improved.