Students entering primary school teacher education at the Faculty of Education, Charles University, usually have quite clear ideas about how and what to teach in mathematics. Within their pre-service education, we aim at building the students' model-for creative, reflective, constructivist, inquiry-based teaching (Gravemeijer, 1999).
These efforts have been supported by encouraging the students to create their professional portfolios. Portfolios are the focus of our research whose main research question is captured by the title of the paper.