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Carnegie Unit

Carnegie Unit

9 September, 2016

Carnegie Unit is a  system developed in the late nineteenth and early twentieth centuries that based the awarding of academic credit on the amount of time students spent in direct contact with a classroom teacher.

  • The standard Carnegie unit is defined as 120 hours of contact time with an instructor—i.e., one hour of instruction a day, five days a week, for 24 weeks, or 7,200 minutes of instructional time over the course of an academic year.

In most public high schools, course credits are still largely based on the 120-hour Carnegie-unit standard.

Most states and American high schools require students to earn between 18 and 24 credits—with each credit representing one Carnegie unit—to be eligible for a diploma. Yet some high schools are moving away from the traditional grading, crediting, grade-promotion, and graduation systems based on contact hours with a teacher. In these schools, grades, credits, and decision about grade promotion and graduation are based on student demonstrating proficiency in meeting required learning standards.


  • Named after American industrialist Andrew Carnegie (1835–1919), a Scottish-born immigrant who accumulated a fortune in steel production before selling the Carnegie Steel Company for $480 million to J.P. Morgan in 1901. After the sale, Carnegie was one of the wealthiest men in the world and he became a philanthropist who invested in causes related to education, libraries, the arts, and world peace.
  • The Carnegie unit became widely used during a time when efforts were being made across the country to standardize public education and ensure that schools applied more uniform, consistent, and effective teaching methods and learning expectations when educating students. Still, the 120-hour Carnegie unit did not achieve widespread adoption by schools and colleges until the Carnegie Foundation for the Advancement of Teaching, which was established in 1906, began to provide retirement pensions for university professors—with the stipulation that participating universities must adopt the Carnegie-unit system. Today, the retirement fund is known as TIAA-CREF. As a result of this decision, by 1910 nearly all the colleges and secondary schools in the United States were using the 120-hour standard to award course credits and determine progress toward graduation.
  • However, during a speech in 1993, Ernest L. Boyer, then president of the Carnegie Foundation for the Advancement of Teaching, made the following statement: “I am convinced the time has come to bury, once and for all, the old Carnegie unit. Further, since the Foundation I now head created this academic measurement a century ago, I feel authorized this morning to officially declare the Carnegie unit obsolete.” Boyer later wrote: “I urgently hope we can move beyond the old Carnegie units. I find it disturbing that students can complete the required courses, receive a high school diploma, and still fail to gain a more coherent view of knowledge and a more integrated, more authentic view of life.”


  • The awarding of academic credit should be based on demonstrated student achievement and learning progress rather than on how many hours students spend in class (often called “seat time” by educators). The criticism arises from the fact that credits based on contact hours may have different meaning, in terms of learning acquisition and progress, from student to student or course to course. For example, students might earn a minimum passing grade in a course and yet still receive credit without having demonstrated that they have achieved expected learning standardsor acquired the essential skills taught in the course. Different teachers may also apply different grading schemes or learning expectations from course to course, so that a “B” in one course means something much different than a “B” earned in a similar course.
  • Critics claim that course credits based on contact time do not certify competency, and they may permit students to progress in their education and earn a diploma even though they have major learning gapsor educational deficiencies.