I was born and grew up in Chile and have lived and worked in Israel since 1971. My research activities lie in three complementary areas within the field of Teacher Education: Mentoring and the development of expertise, learning by professionals and learning in the workplace. My professional work is grounded in a strong ideological, educational, and pedagogical position on the crucial importance of the applied conceptualization of teacher learning and teacher education or, put differently, on the need for grounding theory in practical action. In the area of mentoring, I conceptualize mentoring as a manifestation of the acquisition of professional expertise, as it relates to knowledge development, beliefs, morality, pedagogy, exemplary practice, and contextual and discursive aspects of professional practice. I have also extended the above perspective to the development of professional expertise, the study of collaborative knowledge construction in professional conversations, methodological conceptualizations on the study of professional learning and ethical and cultural groundings of mentoring and mentored learning and their effects on teaching. During the past years I have become particularly engaged in studying how professional mediation is understood and manifested in the design of pedagogies and methodologies in teacher education curricula across cultural and geographical contexts. Connected to this, I also investigate how workplace context mediates the learning of novice teachers in the initial stages of their careers.