During the period 1993–1998 (Godino, 1996; Godino,& Batanero, 1994, 1998), we progressively developed and refined the notions of ‘‘institutional and personal meaning2 of a mathematical object’’ and their relationship to the notion of understanding. Starting from pragmatic assumptions, these ideas try to focus the interest of research on the institutional mathematical knowledge, without dismissing the individualn subject towards which the educational effort is mainly addressed