College & Workforce Readiness What the Research Says

The High School Credit-Hour: A Timeline of the Carnegie Unit

By Sarah D. Sparks — December 15, 2022 4 min read
Shadows of Walla Walla (Wash.) High School seniors waiting to enter graduation are cast on a school wall.
  • Save to favorites
  • Print

The credit-hour, often known as the Carnegie unit, has been the essential measure of American secondary and higher education for more than a century.

Now the Carnegie Foundation for the Advancement of Teaching, which developed the time-based system in 1906, wants to consign it to history. The foundation has just launched what foundation President Tim Knowles expects to be a decade-long research, practice, and legislative initiative to replace time as the essential measure of learning.

That would be a major change for a measurement unit that has become so firmly embedded in the nation’s education system, although not without some long-running criticism.

Here are some key points in time in the evolution of the time-based credit system.

1905

Industrialist Andrew Carnegie donates $10 million (more than $304 million in today’s money) to create a retirement pension fund for teachers in colleges, universities, and technical schools (which became TIAA-CREF). Trustees from the newly created Carnegie Foundation for the Advancement of Teaching realize that there are no standards to distinguish high schools and various types of postsecondary institutions.

Andrew Carnegie, founder of the Carnegie Steel Company, in his study in New York.

1906

In the journal Science, the foundation proposes the need for a new metric to define education. Ultimately, the Carnegie unit measures the amount of time a student studies a subject with a teacher. One “student hour” could include “lecture, lab work, or recitation room work, for a single pupil.” One hundred twenty hours equal one “credit.” Fourteen credits are the minimum for four years of high school preparation. The foundation agrees to back teacher pensions for any postsecondary institution that follows a 120-hour credit standard.

1910

Engineer Morris Llewellyn Cooke, releases the 133-page report, “Academic and Industrial Efficiency,” linking education standards to the then-popular “scientific management” movement he helped promote. Scientific management, launched by fellow engineer Frederick Taylor, aimed to analyze and measure work processes to improve labor efficiency, originally in factories. Cooke’s report advised universities to adopt Carnegie’s “student hour,” with each course credit representing three student-hours a week for 16 weeks. He proposed the system be used to calculate building and staff expenses for university budgets.

1961

Sydney Besvinick, a University of Miami professor, publishes a critique of the Carnegie unit in the magazine Phi Delta Kappan, arguing it is being used as a measure of the quality of learning, when it was designed only as a measure of a student’s exposure to content.

1964

The federal Higher Education Act significantly increased federal financial aid, using student-hours as a measure of programs.

U.S. President Lyndon B. Johnson, seated at the desk he used while a student secretary at Southwest Texas State College 35 years ago, signs the Higher Education Act at San Marcos, Texas, Nov. 8, 1965. Looking over the president's shoulder is Lady Bird Johnson and to her right are, Mrs. Jake Pickle; Rep. James Jarrell "Jake" Pickle, D-Texas; J.C. Kellam, of Austin, partially hidden; and James H. McCrocklin, president of the college. The men at extreme left are not identified.

1992

The Florida Commission on Education Reform and Accountability’s “Blueprint 2000,” is one of several critiques of the time-based credit system among states and think tanks in the 1990s. It argues that time-based credits focus on labels of classes rather than measures of what students know and can do in each subject.

2005

U.S. Secretary of Education Margaret Spellings launches the Commission on the Future of Higher Education, which urges higher education institutions to collect individual student data and report measures of “meaningful student learning outcomes,” not just seat time.

U.S. Secretary of Education Margaret Spellings speaks to a luncheon held to address the future of New Jersey's high schools, sponsored by the group New Jersey United for Higher Education on Wednesday, Feb. 22, 2006 at Fairleigh Dickinson University in Madison, N.J.

2006

Global ministers of education meet in Athens under the auspices of the Organization for International Cooperation and Development, which administers the Program for International Student Assessment, to discuss the need for more comprehensive measures of learning in high school and higher education. The group begins work on a project to compare practices by multiple countries.

2011

As part of revisions to federal financial aid program regulations, the U.S. Department of Education attempts to create a national definition for the student-hour. The proposal sparks sharp criticism, including a letter signed by more than 70 higher education groups, who argue it conflates seat time and learning outcomes.

2012

The New America Foundation releases a report arguing that time-based credit has become less useful for the rising number of students taking online classes and attending college part-time. The Bill & Melinda Gates Foundation dedicates funding to explore mastery-based and other non-time-based credit systems, and states like New Hampshire begin piloting mastery systems.

2013

In his announcement of the federal High School Redesign Initiative, Education Secretary Arne Duncan calls for high school credit to be “defined by learning outcomes, not ‘seat time’ requirements.”

President Barack Obama and Education Secretary Arne Duncan visit a classroom at the Pathways in Technology Early College High School (P-TECH) in Brooklyn, New York, Oct. 25, 2013.

2015

After two years of work by a national task force, the Carnegie Foundation for the Advancement of Teaching publishes a report on time-based credit, defending the use of the Carnegie unit and student-hour as problematic, but the best broadly available measure of student learning.

121522 Carnegie Unit BS

2020

As the COVID-19 pandemic prompts long-term, widespread closures across schools and universities, the majority of states waive or add flexibility to the credits required for high school graduation and the seat time needed to complete them. As the pandemic continues, some states extend this flexibility and look for more ways to expand non-time-based credit systems.

2022

Tim Knowles, the 10th president of the Carnegie Foundation for the Advancement of Teaching, announces an initiative to replace the Carnegie unit, saying: “It seems past time to think about how do you build a legitimately outcomes-based system where learning can happen anywhere.”

Sources: The Carnegie Unit: A Century-Old Standard in a Changing Education Landscape; “Cracking the Credit Hour"; Education Week and other news reports

Events

This content is provided by our sponsor. It is not written by and does not necessarily reflect the views of Education Week's editorial staff.
Sponsor
Classroom Technology Webinar
Better Tools, Not More: What Educators Say About Teaching and Technology
Optimism is up. AI use is rising. Coherence is the next challenge. Hear what the 2026 Educator Confidence Report reveals about the field.
Content provided by HMH
This content is provided by our sponsor. It is not written by and does not necessarily reflect the views of Education Week's editorial staff.
Sponsor
Student Achievement Webinar
The Relationship Advantage for Attendance, Engagement, and Achievement
Relationship-building goes beyond back-to-school. Get practical ideas from district leaders and educators to strengthen student connections.
School & District Management Webinar EdMarketer Quick Hit: Build Campaigns That Engage K-12 Leaders
We’ll share what’s resonating with Education Week’s K-12 audience based on user behavior across platforms and other proprietary data.

EdWeek Top School Jobs

Teacher Jobs
Search over ten thousand teaching jobs nationwide — elementary, middle, high school and more.
View Jobs
Principal Jobs
Find hundreds of jobs for principals, assistant principals, and other school leadership roles.
View Jobs
Administrator Jobs
Over a thousand district-level jobs: superintendents, directors, more.
View Jobs
Support Staff Jobs
Search thousands of jobs, from paraprofessionals to counselors and more.
View Jobs

Read Next

This content is provided by our sponsor. It is not written by and does not necessarily reflect the views of Education Week's editorial staff.
Sponsor
College & Workforce Readiness Quiz
Quiz Yourself: How Much Do You Know About Dual Enrollment?
Find out how much you know about college credit eligibility, cost, and postsecondary outcomes for dual enrollment courses.
Content provided by Pearson
College & Workforce Readiness Post-High-School Outcomes Vary Around the World. How Do U.S. Graduates Stack Up?
Globally, fewer young adults are adrift without college or careers, according to new OECD data.
2 min read
Collage of a person wearing high heels and a graduation gown stepping up stairs that are made of bar charts.
Illustration by Emily Wright for Education Week + Getty
College & Workforce Readiness Transportation Is a Challenge for CTE Programs. How Districts Are Solving It
One district found innovative ways around this barrier.
4 min read
A school bus crosses over U.S. 160 from the Navajo Nation, left, onto the Hopi reservation, right, Monday, March 4, 2024, in Tuba City, Ariz. U.S. Highway 160 is the de facto border between the Navajo and Hopi Indian reservations and two time zones. Mind-bending time calculations is what people in the largest Native American reservation in the U.S. have to endure every March through November. The Navajo Nation, which stretches into Utah and New Mexico, will reset clocks for one hour later despite the rest of Arizona remaining on standard time.
A school bus crosses over U.S. 160 from the Navajo Nation, left, onto the Hopi reservation, right, on March 4, 2024, in Tuba City, Ariz. For school districts that offer offsite work-based learning experiences, transportation is a key challenge.
Matt York/AP
College & Workforce Readiness Why Schools, Colleges, and Employers Aren't Connected on Career-Technical Education
Too much data on education and the labor market exist in silos, a new report finds.
6 min read
South Career and Technical Academy student ambassadors and student councils hand out wristbands to new students as they arrives at CCSD’s newest high school, opening its doors for the 2025-2026 school year, on Aug. 11, 2025 , in Las Vegas .
South Career and Technical Academy students hand out wristbands to new students as they arrive at their school system's newest high school on Aug. 11, 2025, in Las Vegas. A new report recommends that school, college, and workforce leaders break down silos in their data, in order to better coordinate career-technical education goals.
Bizuayehu Tesfaye/Las Vegas Review-Journal via TNS