REU sites typically consist of ten undergraduates working in the research program of the host institution either in the US or abroad, for example,
CERN. As the program is funded by the NSF, undergraduates must be citizens or permanent residents of the US or its possessions to be eligible for funding. However, some REU sites accept "self-funder" international students. Applications are typically due between February and the end of April. The length of the application ranges from a single letter of reference without supporting materials all the way up to something comparable to a college admissions application. The programs generally require between one and three letters of reference, a transcript, 0-2 essays, a letter of interest, a resume, a biographical form, or some combination thereof. Although all eligible students are encouraged to apply, there is an emphasis on including populations underrepresented in science—women, underrepresented minorities, and persons with disabilities.
REU individual experiences typically consist of one undergraduate student, or two undergraduate students working together. Sometimes these undergraduates work with a larger research team that includes graduate students. These REU experiences take place at the student's current university, and can last anywhere from a few weeks to an entire year. The application process varies by the particular faculty member who plans to work with these students. ==Compensation==