Major college rankings organizations, such as “U.S. News & World Report,” “Times Higher Education” and “QS World University Rankings,” all consider how frequently faculty members at each institution publish, as well as how many other scholars cite their publications. Many use the h-index, which J. E. Hirsch defined in the “Proceedings of the National Academy of Sciences” in 2005, to quantify both the quality and the quantity of publications. Some rankings also design formulas with which to account for external grants awarded to faculty, as well as other honors and awards such as membership in the National Academy of Arts and Sciences.
Quantitative metrics regarding students include the student retention rate, which measures how many incoming, first-time freshmen enroll for a second year, and six-year graduation rate, which measures the proportion of each graduating class that graduated within six years. Student-body diversity can also be measured quantitatively, but rankings organizations must decide the relative weights of diversity markers such as gender, race and ethnicity, country of origin, and socioeconomic status. This decision is a qualitative interpretation of quantitative data. Finally, most rankings want to measure the learning experience that each college offers. This measurement can involve quantitative elements such as the student-faculty ratio, but it also often relies on qualitative data such as student surveys conducted by the National Survey of Student Engagement.
Many rankings organizations see exclusivity as a positive trait for colleges, and they therefore include a selectivity category in their ranking formula. This metric relies on quantitative measures such as the SAT and ACT scores of admitted students, admitted students’ class rank in high school and the college’s overall acceptance rate, or proportion of admitted students to applicants. These are also known as “input measures.”
Academic and employer reputations are perhaps the most qualitative metrics that rankings organizations use to rate and rank colleges. Each organization designs its own survey that asks faculty members at a sample of colleges to rate the academic excellence of the colleges being ranked. It sends a separate survey to employers in the private and public sectors asking them to rate the quality of graduates from each college to be ranked. While academic reputation can be an international metric, most rankings organizations only survey employer reputation at the domestic level.