Tomas Hojgaard is Associate Professor of Mathematics Education at Aarhus University, Denmark. His research very often involves an investigation of the opportunities for and challenges in applying descriptions of subject-specific competencies as didactical tools of development, both in general terms, and in relation to mathematical modelling competency. Furthermore, he investigates the conditions for and obstacles against establishing a fertile interplay between didactics of mathematics as a field of research on the one hand, and the practical teaching of mathematics on the other. This is done in various ways, e.g. through participation in a number of R&D-projects.