 Most classes rely on a combination of lectures, recitations led by associate professors or graduate students, weekly problem sets ("p-sets"), and periodic quizzes or tests. While the pace and difficulty of MIT coursework has been compared to "drinking from a fire hose", the freshmen retention rate at MIT is similar other research universities. The "pass / no-record" grading system relieves some pressure for first-year undergraduates. For each class taken in the fall term, freshmen transcripts will either report only that the class was passed, or otherwise not have any record of it. In the spring term, passing grades (A, B, C) appear on the transcript while non-passing grades are again not recorded. (Grading had previously been "pass / no record" all freshman year, but was amended for the Class of 2006 to prevent students from gaming the system by completing required major classes in their freshman year.) Also, freshmen may choose to join alternative learning communities, such as Experimental Study Group, Concourse, or Terrascope.
