By Jane Bennett Clark, Senior Editor December 30, 2011 How to Read the RankingsKiplinger's bases its rankings on a combination of academics and affordability. We start with data from more than 500 public four-year schools, provided by Peterson's/Nelnet, then add our own reporting.SEE OUR SLIDE SHOW: 10 Top Values in Public Colleges, 2012 We narrow the list to about 120 schools based on measures of academic quality -- including SAT or ACT scores, admission and retention rates, student-faculty ratios, and four- and six-year graduation rates, which most schools reported for the class that entered in 2004. We then rank each school based on cost and financial aid. Academic quality carries more weight than costs. To assess costs, we look at the total expenses for in-state students (tuition, mandatory fees, room and board, and books); the average cost for a student with need after subtracting grants (but not loans); the average cost for a student without need after subtracting non-need-based grants; the average percentage of need met by aid; the percentage of students who borrow; and the average debt per student borrower at graduation. Advertisement To determine out-of-state rankings, we run the academic-quality and expense numbers again, this time using total costs for out-of-state residents and average costs after financial aid. Our rankings focus on traditional four-year schools with broad-based curricula. As a result, schools that offer great value but focus on special or narrow academic programs, such as the military service academies, are excluded. Cornell University, best known as a member of the Ivy League, is another exception. Four of Cornell's colleges are part of the privately endowed university, which we consider a private institution. But three of Cornell's undergraduate colleges are land-grant state schools that cost much less -- about $25,000 a year for tuition and fees. How We Calculate Value Cost and financial aid (33%): We consider low sticker prices, generous need-based aid, and percentage of need met (the extent to which financial aid bridges the gap between the family’s expected contribution and the cost of attendance). Advertisement Student indebtedness (14%): With student borrowing on the rise, we now give extra points for low average debt at graduation and low percentage of students who borrow. Competitiveness (22%): High test scores among incoming freshmen, a low admission rate and a high yield (the percentage of accepted applicants who enroll) indicate selectivity and intellectual synergy. Graduation rates (18%): The sooner your kid gets a diploma, the more money you save. We give maximum points for the four-year graduation rate and half that amount for a strong six-year rate. Academic support (13%): The number of students per faculty and the freshman retention rate measure the school’s ability to support its academic mission. Marc A. Wojno, Jonny Jaldin, John Miley, Lauren Muthler, Susannah Snider and Michael Stratford compiled the data.