Initially, research on formative assessment of learning resulted from isolated initiatives, without having shared meaning in the scientific community, rendering its portrait difficult. Forty years later, and with the multiplication of studies resulting from the wave of educational reforms in western societies in the past decade, it now becomes possible to gain a clear scope of the constituted field. It now distinguishes itself by various tendencies of research, gathered around different objects specifically attached to formative assessment. This contribution aims to give an overview of this research by considering what is done both in the Francophone and the Anglophone communities. As we will see, parallel to well known instrumental reasoning, now emerges informal methods stemming from strategies put into place by teachers in the flow of interactions taking place in the classroom.