EFFECTIVE 'BLENDED' PROFESSIONAL DEVELOPMENT FOR TEACHERS OF MATHEMATICS: DESIGN AND EVALUATION OF THE "UPOLA"-PROGRAM

The paper describes the implementation and evaluation of UPOLA, a one-year-long blended learning professional development (PD) program for teachers of mathematics. The use of polyvalent tasks in classes as the main issue of UPOLA proved to be appropriate to support changes in classroom practice. Based on a short overview of the concept of polyvalent tasks, a description of the design of the blended professional program is given by considering multiple dimensions of 'blending'. The evaluation of the program shows a shift in participants' perception over the time from rather environmental variables towards the impact of UPOLA for teachers' acting and students' learning. Furthermore, some findings on the implementation of web-based communication and collaboration are presented.