Academic Term - Terminology

Terminology

A 'semester' (from the Latin meaning "six-monthly", or Semi-, half) has come to mean either of two academic terms, generally excluding the summer or January terms, if any, and so can be 14 to 20 weeks long. The word 'semester' is sometimes used as a synonym for a 'term', as in a 'summer semester'.

A 'trimester' (from the Latin meaning "three-monthly") divides the academic year into three periods. At the University of Michigan, for example, the Fall trimester (informally still called 'semester') operates from September through December; the Winter trimester runs from January through April; and the Spring-Summer trimester operates from May through August, as two half-trimesters. Most Spring-Summer classes either meet double-time for 7 – 8 weeks in May and June or double-time/double-plus-time for 6 – 8 weeks in July and August (with summer half-term classes sometimes starting in the last week of June). In some jurisdictions, "trimester" is used in its original meaning to indicate a quarter system (since three months is exactly a quarter of a year), or a variation of it.

A 'quarter' or 'quadmester' system treats the summer term on an equal footing with the other terms. It divides the academic year into four quarters, each of which is usually 12 weeks long. Three of the four quarters - Fall, Winter and Spring, operating from September through June or August through May, are thus equivalent to two 18-week semesters. Thus, when American academic universities convert academic credits between the semester/trimester and quarter systems, 36 quarter hours convert to 24 semester hours (2/3 conversion factor) while 36 semester hours convert to 54 quarter hours (3/2 conversion factor).