After obtaining a master degree or a research master degree, candidates can apply for a PhD position in the Dutch system of higher education. The main task of a PhD candidate is to do research and write a dissertation. PhD candidates spend about 75% of their time on their PhD research project. The rest of time is for their education (about 15% of the time) and tasks in teaching (about 10% of the time). The PhD position usually takes 3 - 4 years and sometimes longer in case of a part-time appointment.