Traditionally there were no formalized curricula for doctoral studies. Graduate education was based on the training of researchers through a doctoral dissertation preparation process under a professoris guidance. While this approach allows in-depth guidance, there are also disadvantages, including a tendency to focus on narrow research themes. In recent years a more organized and efficient system has been introduced in addition to the traditional method. Under the new system doctoral candidates studying specific themes are organized into groups led by a number of professors and undertaking education and research over a three-year period. Efforts are now being made to expand this system.