The initial appointment is for one year, and is renewable for another year. It also includes a commitment for life to support shorter visits to Germany in the future, should Paul desire to continue his collaboration with German scientists.
The Humboldt Research Fellowships are awarded to "highly qualified, foreign scientists and scholars of all nationalities and disciplines holding doctorates, aged up to 40, from abroad for a long-term research stay in Germany (up to 600 fellowships per annum)". They are offered world-wide on a competitive basis. The most important criteria for selection are the applicant's international publications to date and the quality and feasibility of the research proposal.