According the free encyclopedia (Wikipedia), a supervisor is first and foremost an overseer, whose main responsibility is to ensure that a group of subordinates get out the assigned amount of production, when they are supposed to do it and within acceptable levels of quality, costs and safety. Thus, a supervisor is responsible for the productivity and actions of a small group of students.
During my supervisor exercise at the University of Brasília, from 2003 to 2011, I had 14 undergraduate research program (PIBIC),
17 MSc students with awarded diploma and 2 still doing the course, 2 ongoing PhD students (started 2008 and 2009) and 2 ongoing joint supervisions (started 2010). The students are presented in each respective page (PhD, MSc and PIBIC).