1. Faculty of Education, University of the Free State, Bloemfontein, South Africa
2. Dean Faculty of Education and SANRAL Chair in Mathematics, Natural Sciences and Technology Education, University of the Free State, Bloemfontein, South Africa and School of Mathematics, Natural Sciences and Technology Education, Faculty of Education, University of the Free State, Bloemfontein, South Africa
3. Department of Curriculum Studies and Higher Education, Faculty of Education, University of the Free State, Bloemfontein, South Africa