Introduction to the papers of TWG19: Mathematics teacher and classroom practices

International audienceThis Thematic Working Group (TWG) together with TWG18 and TWG20 addresses questions related to mathematics teachers, teaching, and their development. TWG19 focuses particularly on mathematics teaching, including important micro and macro factors that frame it. Classroom research has been the focus for many years in mathematics education, but new theoretical and methodological directions have been reported in this group aiming to study on the one hand the overall complexity of teaching and on the other the particular aspects that characterize it