How do researchers determine what is true based on the data they collect? This question is one of the central concerns of statistics, which uses mathematical models to draw useful conclusions about the real world.

Many students earn associate degrees during their first few years of higher education. Since they usually require about two years of study, these degrees can act either as job qualifications or as precursors to more advanced degrees.

Part-time learning allows one to obtain a degree or qualification even if one cannot attend school on a full-time basis. One can learn at one's own pace, gradually accumulating credits that count towards a final qualification.