CREDIT HOUR STANDARDS
Credit Hours are based on the broadly used Carnegie Unit
The Carnegie Unit and the Student Hour (also called a Credit Hour) are strictly time-based references for measuring educational attainment used by American universities and colleges; the Carnegie Unit assesses secondary school attainment, and the Student Hour, derived from the Carnegie Unit, assesses collegiate attainment. Per its original definition, the Carnegie Unit is 120 hours of class or contact time with an instructor over the course of a year at the secondary (American high school) level. The Student Hour is approximately 12 hours of class or contact time. As it is used today, a Student Hour is the equivalent of one hour (50 minutes) of lecture time for a single student per week over the course of a semester, usually 14 to 16 weeks.
In a college or university, students typically receive credit hours based on the number of "contact hours" per week in class, for one term; formally, Semester Credit Hours. A contact hour includes any lecture or lab time when the professor is teaching the student or coaching the student while they apply the course information to an activity. Regardless of the duration of the course (i.e. short semesters like summer or intersession) and depending on the state or jurisdiction, a semester credit hour (SCH) is 15-16 contact hours per semester. Most college and university courses are 3 Semester Credit Hours SCH or 45-48 contact hours, so they typically meet for three hours per week over a 15 week semester. To provide students with the minimum 45-48 contact hours while accounting for holidays, college start dates, etc., many courses will have 50 or more contact hours. Otherwise, a Monday (or Monday/Wednesday/Friday) course may have only 42 contact hours, while a Tuesday (or Tuesday/Thursday) course may have 48 contact hours.
Homework is time the student spends applying the class material without supervision of the professor: this includes studying notes, supplementary reading, writing papers, or other unsupervised activities like lab work or field work. Because students are generally expected to spend three hours outside class studying and doing homework for every hour spent in class, 15 SCH is a full course load.
Credit for laboratory and studio courses as well as physical education courses, internships and practicum is usually less than for lectures - typically one credit for every two to three hours spent in lab or studio, depending on the amount of actual instruction necessary prior to lab. However, for some field experiences such as student teaching as a requirement for earning one's teaching license, a student may only earn 8-10 credits for the semester for doing 40 hours a week of work.
Credit by examination is a way of receiving course credit without taking the course. This grade often shows as a "K" on a transcript, however it carries no credit hours, and therefore has no effect on the GPA. This also means that a student often must take other classes instead, to meet minimum hour requirements. (This still benefits the student, because he or she can learn something new and useful, instead of repeating what is already known.)
*Edited From Wikipedia, the free encyclopedia